This week, Friday, 9 October, 2009, NASA will send a missile into the Moon at twice the speed of a bullet. As part of the LCROSS (Lunar CRater Observing and Sensing Satellite) mission, scientists have selected a target close to the Moon's south pole. At this time the plan is to target crater Cabeus A, but the exact location is still being determined based on data and information that scientists and mission controllers are gathering as the satellite approaches the moon.
This mission was launched back in June and is part of an ongoing program that NASA has to try and find any water ice that might be trapped in crater shadows. The Moon is primarily an airless, dusty/rocky desert and about the only place where water could be trapped is in areas that do not receive any sunlight. Water is a critical component in making any manned moonbase project a success. Transporting water and other goods from Earth to the moon's surface is expensive. Finding natural resources, such as water ice, on the moon could help expedite lunar exploration.
The missile impact is expected to be so powerful that a huge plume of debris will be ejected. Just as the impact of the Shoemaker-Levy comet fragments into Jupiter revealed a lot of information on the compostion of Jupiter's atmosphere, scientists hope hope that water ice or water vapour will be ejected in the cloud that is thrown up from the impact. As the ejecta rises above the target crater’s rim and is exposed to sunlight, any water-ice, hydrocarbons or organics will vaporize and break down into their basic components.
Following the missile, another part of the spacecraft will be taking pictures and analyzing the ejecta for evidence of water. The instruments include two near-infrared spectrometers, a visible light spectrometer, two mid-infrared cameras, two near-infrared cameras, a visible camera and a visible radiometer. The spectrometers analyze the breakdown of the ejecta materials into their basic components. The infrared cameras will help determine the amount and distribution of the water vapor and the visible camera will tract the location of the impact and the debris plume.
All this will take place in just four minutes and then this craft itself will crash into the Moon itself, producing an even more spectacular explosion. What is interesting about this is that this second explosion should be visible in the 10-12 inch and larger telescopes of amateur astronomers! The projected impact at the lunar South Pole is currently: Oct 9, 2009 at 4:30 a.m. Pacific Daylight Savings Time, which is 9 hours behind Central European Daylight Savings Time of 1:30 PM. So we in Europe won't get much chance to have a peak, but if you get up early enough in the US, depending on where you are, you might be able to see it.
Otherwise, NASA will be providing a live broadcast of this event starting at 3:15 AM PDT which can be seen online: www.nasa.gov/ntv. Additional information on the LCROSS mission can be found here: www.nasa.gov/mission_pages/LCROSS/main/index.html.
No, this is not an attack on an alien base on the moon. Nor is it a misguided attempt of Obama's administration to root out a new Al-Qaeda hiding place. It is not vandalism or scientist's frustration with the lack of funding for space science. It is a valid and useful experiment and a good way to find information without the expense and hazards of a moon landing to bring back samples to Earth.
And while there is some controversy about such an experiment, it should be noted that this is not the first impact by spacecraft on the moon. This past June, the Japan space agency, JAXA, sent its robotic probe, the Kaguya spacecraft, on a controlled impact into the moon after the completion of its mission and the exhaustion of its fuel supply. As this happened on the dark side of the moon, there was not a reach chance to view the ejecta from the impact, but there was a brilliant explosion that was caused purely by the energy of the impact and it was viewed by a number of astronomers with some spectacular images captured by the Anglo-Australian Telescope in New South Wales.
And in 2006, ESA's SMART-1 concluded its scientific observations of the Moon through a small impact on the lunar surface. This kind of conclusion to a lunar mission has actually been common through the years and scientists have watched them closely, gleaning what additional data they could from the debris of such impacts. Observatories around the world have conducted fast imaging of impacts and of the associated ejected material, and spectroscopic analysis, to try and find hints about the mineralogy of the impact areas.
However, this "accepted practice" has not caused the controversy in the past that this week's mission has raised, with some folks exaggerating the impact crater size as being up to 5 miles, others stating that it "...is contrary to space law prohibiting environmental modification of celestial bodies." And even some folks worried about it triggering potential "...conflict with known extraterrestrial civilizations on the moon as reported on the moon in witnessed statements by U.S. astronauts." *sigh*
In truth, there is no actual explosives on board, and the impact vehicle is just the upper stage of the rocket that launched the mission in the first place. It is estimated that it will excavate a crater approximately 20 meters wide and almost 3 meters deep and more than 250 metric tons of lunar dust will be lofted above the surface of the moon. It is not expected to be a spectacular explosion. Though at this time it is unknown about the kind of response we can expect to get from the lunar aliens... (this last sentence is just a joke!!!)
Showing posts with label Astronomy. Show all posts
Showing posts with label Astronomy. Show all posts
Wednesday, October 7, 2009
Monday, February 18, 2008
Good Night Moon...
Thalia's Child from Musings from a Muse gave me this award:
She said, "This woman's brain intimidates me..." Now I'm not quite sure that is a compliment! I don't really want to intimidate anyone. If anything, I try and help explain science to the layman/woman because I don't think it should be intimidating. But I will accept the award in the spirit that it is given and will be passing along my nominees in a future post. (And BTW, thanks Thalia's Child, it is nice to get blog bling!)
But I have heard comments from others who think I am pretty brainy. "Whiked smaaht" as SMID would say! So now I guess I have a reputation to maintain. Therefore I will tell you about the upcoming total lunar eclipse.
This is happening on Wednesday night (20-21.February.2008) and will be visible from most of North America as well as South America, Western Europe, Africa and Western Asia.
A total lunar eclipse is pretty special. Lunar eclipses only occur during the full moon, and while there is usually one of those a month, because the Moon's orbit around the Earth is tipped 5 degrees compared to Earth's orbit around the Sun, the Moon does not usually pass through the Earth's shadow. But about 2 - 4 times a year, it does pass through all or part of the shadow, and an eclipse occurs.
Now maybe you will hear some talking head on the TV speak about partial eclipses, umbral and penumbral shadows, and you'll think "Huh"? This is just fancy scientist talk. The Earth's shadow is actually composed of two cone-shaped parts, one nested inside the other (see diagram below) . The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon. In fact, so little light is blocked during the penumbral lunar eclipses that they are not really visible to the untrained naked eye. But scientists love using big words that no one understands, so one of them might mention this. Ignore this discussion.
More common events are partial lunar eclipses. This is where the Moon passes through only part of the Earth's umbral shadow. That means you see a the Full Moon which gets a "bite" taken out of one side that slowly grows bigger and then gets smaller. There will be a partial lunar eclipse visible from parts of Europe on August 16th this year.
But you really should try and view all or part of the eclipse this week if the weather in your area permits. Some of you in the western US or Australia might have had an opportunity to see the total lunar eclipse in August last year. But another total eclipse will not occur until 2010. So set your alarms or stay up late and hope for good weather!
Here is a table of the viewing times for your locations:
* Event occurs on morning of February 21, 2008
The UK and parts of western Europe are on GMT time. The Netherlands, Germany, etc. are on GMT +1. This means I'll be getting up about 4 AM (yawn!).
So what is so special about a total lunar eclipse? Won't it just look like the Moon going through all its phases within a short space of time? Yes it will. Kind of. Maybe. You see the direct light from the sun will be blocked by the body of the earth. But sunlight also passes through the Earth's atmosphere and bends. So just like dawn and dusk are not completely dark, even though the sun is still below the horizon, some light from the sun will reach the moon and the shadow will not be completely dark. Thus the shadow from an eclipse is not like the "phase" of the moon because no sunlight is shining on the dark part of the moon when it is not "full". (This is a trick question for kids in science, when they say that the dark part of the lunar phase is the shadow of the Earth blocking the Sun from the Moon!)
So what can we expect? The most beautiful total lunar eclipses are when the Earth's atmosphere filters out the blue portions of the sunlight and only allows the redder portions of the light to come through. So we could see a "blood red moon". In some earlier times and cultures this was a portent of evil or misfortune or the approach of a terrible event. I don't doubt that there will be something that occurs in the coming year that might be linked back to this event. In fact, I will even predict that someone will make this link! Check back with me in a year and I'll be happy to say "I told you so"!
And of course you should look for Mars, which is the reddish object shining brightly just above
Orion. Through the course of the night Mars and Orion descend toward the western horizon.
Saturn is visible as a bright yellowish object in the late evening in the southeast sky.
She said, "This woman's brain intimidates me..." Now I'm not quite sure that is a compliment! I don't really want to intimidate anyone. If anything, I try and help explain science to the layman/woman because I don't think it should be intimidating. But I will accept the award in the spirit that it is given and will be passing along my nominees in a future post. (And BTW, thanks Thalia's Child, it is nice to get blog bling!)But I have heard comments from others who think I am pretty brainy. "Whiked smaaht" as SMID would say! So now I guess I have a reputation to maintain. Therefore I will tell you about the upcoming total lunar eclipse.
This is happening on Wednesday night (20-21.February.2008) and will be visible from most of North America as well as South America, Western Europe, Africa and Western Asia.
A total lunar eclipse is pretty special. Lunar eclipses only occur during the full moon, and while there is usually one of those a month, because the Moon's orbit around the Earth is tipped 5 degrees compared to Earth's orbit around the Sun, the Moon does not usually pass through the Earth's shadow. But about 2 - 4 times a year, it does pass through all or part of the shadow, and an eclipse occurs.
Now maybe you will hear some talking head on the TV speak about partial eclipses, umbral and penumbral shadows, and you'll think "Huh"? This is just fancy scientist talk. The Earth's shadow is actually composed of two cone-shaped parts, one nested inside the other (see diagram below) . The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon. In fact, so little light is blocked during the penumbral lunar eclipses that they are not really visible to the untrained naked eye. But scientists love using big words that no one understands, so one of them might mention this. Ignore this discussion.
More common events are partial lunar eclipses. This is where the Moon passes through only part of the Earth's umbral shadow. That means you see a the Full Moon which gets a "bite" taken out of one side that slowly grows bigger and then gets smaller. There will be a partial lunar eclipse visible from parts of Europe on August 16th this year.
But you really should try and view all or part of the eclipse this week if the weather in your area permits. Some of you in the western US or Australia might have had an opportunity to see the total lunar eclipse in August last year. But another total eclipse will not occur until 2010. So set your alarms or stay up late and hope for good weather!
Here is a table of the viewing times for your locations:
| Total Lunar Eclipse of February 20, 2008 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| North America | Other | ||||||||
| Event | AST | PST | MST | CST | EST | GMT | GMT+1h | GMT+2h | |
| Partial Eclipse Begins: | 04:43 pm | 05:43 pm | 06:43 pm | 07:43 pm | 08:43 pm | 01:43 am* | 02:43 am* | 03:43 am* | |
| Total Eclipse Begins: | 06:01 pm | 07:01 pm | 08:01 pm | 09:01 pm | 10:01 pm | 03:01 am* | 04:01 am* | 05:01 am* | |
| Mid-Eclipse: | 06:26 pm | 07:26 pm | 08:26 pm | 9:26 pm | 10:26 pm | 03:26 am* | 04:26 am* | 05:26 am* | |
| Total Eclipse Ends: | 06:51 pm | 07:51 pm | 08:51 pm | 09:51 pm | 10:51 pm | 03:51 am* | 04:51 am* | 05:51 am* | |
| Partial Eclipse Ends: | 08:09 am* | 09:09 pm | 10:09 pm | 11:09 pm | 12:09 pm | 05:09 am* | 06:09 am* | 07:09 am* | |
The UK and parts of western Europe are on GMT time. The Netherlands, Germany, etc. are on GMT +1. This means I'll be getting up about 4 AM (yawn!).
So what is so special about a total lunar eclipse? Won't it just look like the Moon going through all its phases within a short space of time? Yes it will. Kind of. Maybe. You see the direct light from the sun will be blocked by the body of the earth. But sunlight also passes through the Earth's atmosphere and bends. So just like dawn and dusk are not completely dark, even though the sun is still below the horizon, some light from the sun will reach the moon and the shadow will not be completely dark. Thus the shadow from an eclipse is not like the "phase" of the moon because no sunlight is shining on the dark part of the moon when it is not "full". (This is a trick question for kids in science, when they say that the dark part of the lunar phase is the shadow of the Earth blocking the Sun from the Moon!)
So what can we expect? The most beautiful total lunar eclipses are when the Earth's atmosphere filters out the blue portions of the sunlight and only allows the redder portions of the light to come through. So we could see a "blood red moon". In some earlier times and cultures this was a portent of evil or misfortune or the approach of a terrible event. I don't doubt that there will be something that occurs in the coming year that might be linked back to this event. In fact, I will even predict that someone will make this link! Check back with me in a year and I'll be happy to say "I told you so"!
If the Earth had no atmosphere, then the Moon would be completely black during a total lunar eclipse. But it can actually take on a range of colors and even change during the event. It can range from yellow to orange or red to dark brown. It will depend on how much dust, pollution and clouds are present in the atmosphere. After the volcano on Mount Pinatubo in 1992, the December total lunar eclipse was dark brown and almost black.
And of course you should look for Mars, which is the reddish object shining brightly just above
Orion. Through the course of the night Mars and Orion descend toward the western horizon.
Saturn is visible as a bright yellowish object in the late evening in the southeast sky.
Friday, August 24, 2007
Google Fun!
Google Earth now has an upgrade which is literally "out of this world" . With this upgrade you can now cruise the heaven from your home/desktop computer. Now supernovas, galaxies and all sort of celestial phenomena are only a mouse click away.
The upgrade is ‘Sky in Google Earth’, and it can be downloaded free of charge with the newest version of Google Earth. Now in just a few seconds, anyone can view over 120 of the most popular Hubble images. It is fairly simple to operate with drop-down menus and zoom features that are typical of Google Earth.
But this blog is my usual Saturday Silliness, so here is a bit of silly Google Fun. In addition to their Google Earth, there is also a website Google Moon. This is also a really cool website with the landing sites of all the Apollo missions indicated. Any of these features can be clicked on and viewed up-close. The really fun part (show this to your kids!) is when you choose to zoom in really close to see what the moon looks like at the highest definition!
Happy Weekend!!
The upgrade is ‘Sky in Google Earth’, and it can be downloaded free of charge with the newest version of Google Earth. Now in just a few seconds, anyone can view over 120 of the most popular Hubble images. It is fairly simple to operate with drop-down menus and zoom features that are typical of Google Earth.
But this blog is my usual Saturday Silliness, so here is a bit of silly Google Fun. In addition to their Google Earth, there is also a website Google Moon. This is also a really cool website with the landing sites of all the Apollo missions indicated. Any of these features can be clicked on and viewed up-close. The really fun part (show this to your kids!) is when you choose to zoom in really close to see what the moon looks like at the highest definition!
Happy Weekend!!
Friday, August 17, 2007
15 Kid-friendly Space/Astronomy sites
I know, you're probably a wee bit tired of all the space stuff I blog about, but I am passionate about Space/Science/Astronomy/Physics, hence my blog title. So no apologies here, you should have known what you're getting into!! Here are only 15 of my favorite Astronomy/Space sites that are especially kid-friendly. Check 'em out!
1. Solar System Coloring Book This is a 13 page coloring book in PDF format, with pictures and associated information on the Solar System. It covers the Sun, Mercury, Venus, Earth, Mars, Asteroids, Jupiter, Saturn, Uranus, Neptune, Pluto and Comets. Learn about the Solar System and color all its planets at the same time. Ages 6 up.
2. Nine (Eight) Planets Solar System Tour A multimedia tour of the Solar System. My favorite place to start with kids in the astronomy classes I teach! Warning, they can spend hours at this site, I know because I have! Ages 8 & up.
3. Astronomy for Kids Not as extensive as #2, but some fun simple explanations. Under the "Your Page" section, kids can email questions that are answered online. Ages 6 & up, but should be able to read.
4. Greatest Photos from Hubble Space Telescope Some fantastic photos!
5. Astronomy Photo of the Day Every day a new picture. Every day something new to marvel at!
6. Kids Astronomy A little bit higher level but has some fun games. Ages 8 & up.
7. NASA's Kid Site Of course NASA also has a special site for kids and it has great activities, games, contests and info about upcoming launches, etc. Great for budding scientists and astronauts! Ages 8 & up.
8. Starchild for Young Astronomers Another NASA sponsored site, with two different levels. Ages 8 & up.
9. Imagine the Universe! A NASA site for older kids. Ages 14 & up.
10. Space Kids Yet another NASA site, but a bit more technical and science oriented. Ages 10 & up.
11. Amazing Space Along with a short video monthly guide to features in the night sky (mentioned in this blog) this site also offers homework help, simple science experiments and investigations, and great games. Ages 10 & up.
12. Astronomy Unbound More of a site for experienced computer users, but worth the effort for those with a serious interest. Ages 10 & up.
13. Zoom Astronomy Various activities about the Solar System Ages 8 & up.
14. ESA for kids The European Space Agency's kids site. Not as extensive as NASA's but tells about European satellites and activities. Ages 8 & up.
15. BBC Science & Nature: Space In the great BBC style, another site to spend hours exploring. Again for experienced computer users, but some fun games. And the other links on the site to the Science & Nature sites are also great. Ages 10 & up.
What? That's 15 already? Oh well, will save the rest for another post!! Have fun exploring!
If you want to visit other Friday Fifteen entries, check out this site!
1. Solar System Coloring Book This is a 13 page coloring book in PDF format, with pictures and associated information on the Solar System. It covers the Sun, Mercury, Venus, Earth, Mars, Asteroids, Jupiter, Saturn, Uranus, Neptune, Pluto and Comets. Learn about the Solar System and color all its planets at the same time. Ages 6 up.
2. Nine (Eight) Planets Solar System Tour A multimedia tour of the Solar System. My favorite place to start with kids in the astronomy classes I teach! Warning, they can spend hours at this site, I know because I have! Ages 8 & up.
3. Astronomy for Kids Not as extensive as #2, but some fun simple explanations. Under the "Your Page" section, kids can email questions that are answered online. Ages 6 & up, but should be able to read.
4. Greatest Photos from Hubble Space Telescope Some fantastic photos!
5. Astronomy Photo of the Day Every day a new picture. Every day something new to marvel at!
6. Kids Astronomy A little bit higher level but has some fun games. Ages 8 & up.
7. NASA's Kid Site Of course NASA also has a special site for kids and it has great activities, games, contests and info about upcoming launches, etc. Great for budding scientists and astronauts! Ages 8 & up.
8. Starchild for Young Astronomers Another NASA sponsored site, with two different levels. Ages 8 & up.
9. Imagine the Universe! A NASA site for older kids. Ages 14 & up.
10. Space Kids Yet another NASA site, but a bit more technical and science oriented. Ages 10 & up.
11. Amazing Space Along with a short video monthly guide to features in the night sky (mentioned in this blog) this site also offers homework help, simple science experiments and investigations, and great games. Ages 10 & up.
12. Astronomy Unbound More of a site for experienced computer users, but worth the effort for those with a serious interest. Ages 10 & up.
13. Zoom Astronomy Various activities about the Solar System Ages 8 & up.
14. ESA for kids The European Space Agency's kids site. Not as extensive as NASA's but tells about European satellites and activities. Ages 8 & up.
15. BBC Science & Nature: Space In the great BBC style, another site to spend hours exploring. Again for experienced computer users, but some fun games. And the other links on the site to the Science & Nature sites are also great. Ages 10 & up.
What? That's 15 already? Oh well, will save the rest for another post!! Have fun exploring!
If you want to visit other Friday Fifteen entries, check out this site!
Friday, August 10, 2007
15 reasons to Look at the Night Sky During August
1. The warm summer nights make for great viewing. Just bring along the bug spray and a blanket to lay on!
2. The most prominent summer constellation is Sagittarius, the Archer, which in the Northern Hemisphere is seen in the southern sky . Look for the group of stars which seem to form the shape of a teapot.
3. When you are looking at Sagittarius, you are looking towards the center of the Milky Way Galaxy.
4. If you are fortunate to be in a "dark sky" location (meaning little or no light pollution from cities, highways, etc.) then you might notice what appears to be "steam" rising from the spout of the teapot. This is what is known as the Milky Way, the dense band of stars that are part of our galaxy.
5. To the right (West) of Sagittarius is the constellation Scorpio, the Scorpion. This is one of my favorite constellations to spot because it looks so much like its name. If you don't have many trees or buildings blocking the SW horizon, then you should be able to see the tail of the scorpion curled around about to sting! The bright star about where the heart or back of the scorpion would be is Antares and should have a red-orange color. Its brightness and color are similar to how the planet Mars appears in the night sky.
6. Looking up from the South towards overhead, you will see a very bright star. This is Vega in the constellation Lyra. It is one of the brightest stars that we can see.
7. Have you spotted Lyra? Now look to the left (East) about 40 degrees and a little above this star, and you should see another very bright star. This is Deneb in the constellation Cygnus (the Swan, which looks like a cross).
8. Look straight down from this star and you will find another bright star, Altair, in the constellation Aquila (the Eagle).
9. The 3 bright stars Vega, Deneb and Altair make up what is known as the "Summer Triangle". It is not one of the 88 official constellations, but has been used by sailors for navigation in the past.
10. If you want to try spotting a deep-sky object, go back to Sagittarius and look for the small triangle which is the teapot's lid. To the left of the top star in this triangle is a small "fuzzy" object, which looks almost like a cloud. Closer inspection with binoculars will show it is a cloud made up of stars. This is known as a globular cluster. (Use this term to impress your friends!) Whereas most of the stars we see in constellations only appear close to one another, in a globular cluster the stars really are close together. This deep-sky object is one of the brightest and one of the few we can see with the naked eye. And astronomically speaking, it is relatively close, only 10,400 light-years distant (that means it takes 10,400 years for light from this object to reach our eyes!)
11. Jupiter continues to be bright during this month, and appears as the "first star" in the southern sky after sunset. With a small telescope or strong binoculars, you should be able to see a couple of its moons!
12. If you can stay up late, Mars rises in the East after midnight. But the best view of it is early in the morning when it is highest in the sky. Look for a reddish-colored "star" that doesn't twinkle.
13. If you were not able to see the Delta Aquarids last month, my favorite meteor shower is coming up this month. This is the Perseid meteor shower. This shower is caused by the debris or dust from multiple visits of the comet Swift-Tuttle which has been left behind in the path of the Earth's orbit. As this debris enters the Earth's atmosphere, the dust burns up in streaks across the sky that we call meteors. It seem that the meteors are all coming from the constellation Perseus. Best viewing starts tomorrow night, Aug11-Aug14 and it should be spectacular as this year the moon comes up very late on these prime viewing dates.
14. For those of you living in the Americas, Australia and eastern Asia, you have a real treat in store on August 28th. This is the date of a lunar eclipse. Look at the moon during the eclipse period (this will vary depending on your location, but should be announced in the newspaper or on TV), and you should notice that the southern (lower) half of the moon looks brighter than the northern (upper) half. This is because the upper part of the moon passes deeper into the Earth's shadow, while the southern half will still receive light filtered through the Earth's atmosphere. There will not be any real boundary between the lighter/darker areas, but it might appear that the lighter area has a reddish tinge.
15. There is a new episode on "Amazing Space" which shows most of this information and more!
Wishing you fine summer weather, clear dark skies and happy viewing!!
If you want to visit other Friday Fifteen entries, check out this site!
2. The most prominent summer constellation is Sagittarius, the Archer, which in the Northern Hemisphere is seen in the southern sky . Look for the group of stars which seem to form the shape of a teapot.
3. When you are looking at Sagittarius, you are looking towards the center of the Milky Way Galaxy.
4. If you are fortunate to be in a "dark sky" location (meaning little or no light pollution from cities, highways, etc.) then you might notice what appears to be "steam" rising from the spout of the teapot. This is what is known as the Milky Way, the dense band of stars that are part of our galaxy.
5. To the right (West) of Sagittarius is the constellation Scorpio, the Scorpion. This is one of my favorite constellations to spot because it looks so much like its name. If you don't have many trees or buildings blocking the SW horizon, then you should be able to see the tail of the scorpion curled around about to sting! The bright star about where the heart or back of the scorpion would be is Antares and should have a red-orange color. Its brightness and color are similar to how the planet Mars appears in the night sky.
6. Looking up from the South towards overhead, you will see a very bright star. This is Vega in the constellation Lyra. It is one of the brightest stars that we can see.
7. Have you spotted Lyra? Now look to the left (East) about 40 degrees and a little above this star, and you should see another very bright star. This is Deneb in the constellation Cygnus (the Swan, which looks like a cross).
8. Look straight down from this star and you will find another bright star, Altair, in the constellation Aquila (the Eagle).
9. The 3 bright stars Vega, Deneb and Altair make up what is known as the "Summer Triangle". It is not one of the 88 official constellations, but has been used by sailors for navigation in the past.
10. If you want to try spotting a deep-sky object, go back to Sagittarius and look for the small triangle which is the teapot's lid. To the left of the top star in this triangle is a small "fuzzy" object, which looks almost like a cloud. Closer inspection with binoculars will show it is a cloud made up of stars. This is known as a globular cluster. (Use this term to impress your friends!) Whereas most of the stars we see in constellations only appear close to one another, in a globular cluster the stars really are close together. This deep-sky object is one of the brightest and one of the few we can see with the naked eye. And astronomically speaking, it is relatively close, only 10,400 light-years distant (that means it takes 10,400 years for light from this object to reach our eyes!)
11. Jupiter continues to be bright during this month, and appears as the "first star" in the southern sky after sunset. With a small telescope or strong binoculars, you should be able to see a couple of its moons!
12. If you can stay up late, Mars rises in the East after midnight. But the best view of it is early in the morning when it is highest in the sky. Look for a reddish-colored "star" that doesn't twinkle.
13. If you were not able to see the Delta Aquarids last month, my favorite meteor shower is coming up this month. This is the Perseid meteor shower. This shower is caused by the debris or dust from multiple visits of the comet Swift-Tuttle which has been left behind in the path of the Earth's orbit. As this debris enters the Earth's atmosphere, the dust burns up in streaks across the sky that we call meteors. It seem that the meteors are all coming from the constellation Perseus. Best viewing starts tomorrow night, Aug11-Aug14 and it should be spectacular as this year the moon comes up very late on these prime viewing dates.
14. For those of you living in the Americas, Australia and eastern Asia, you have a real treat in store on August 28th. This is the date of a lunar eclipse. Look at the moon during the eclipse period (this will vary depending on your location, but should be announced in the newspaper or on TV), and you should notice that the southern (lower) half of the moon looks brighter than the northern (upper) half. This is because the upper part of the moon passes deeper into the Earth's shadow, while the southern half will still receive light filtered through the Earth's atmosphere. There will not be any real boundary between the lighter/darker areas, but it might appear that the lighter area has a reddish tinge.
15. There is a new episode on "Amazing Space" which shows most of this information and more!
Wishing you fine summer weather, clear dark skies and happy viewing!!
If you want to visit other Friday Fifteen entries, check out this site!
Friday, July 20, 2007
The Sky at Night (2)
While preparing for our holiday, I looked up what astronomical events to expect and realized there will be a meteor shower next week. Thought I'd give you all a quick heads up!
This is the Southern Delta Aquarids meteor shower which show up from mid July to mid August each year with peak activity this year on July 28 & 29. This shower gets its name because most of the meteors ("shooting stars") seem to come from the constellation Aquarius, near one of its brightest stars, Delta Aquarii. This is considered to be a "strong" shower, which means there are likely to be a relatively high number of observable meteors. What this means is that under "dark sky" locations where there is not too much light pollution, you could potentially see 15-20 meteors per hour with a possible peak of 60.
If you don't want to get up early, you can start viewing after midnight and by 2AM you should be guaranteed to see some streaks in the sky. The best viewing times are in the pre-dawn hours away from the glow of city lights. Look halfway between the South and Southeast, at between 30 and 60 degrees above the horizon, and if conditions are right you will see meteors fanning out through all compass points from east to north to west with fewer seen heading southward.
The best way of viewing meteors is actually with your peripheral (side) vision as the eye's retina is more sensitive to low light conditions this way. So relax in a good recliner, get your blanket and a hot beverage (even on warm days it can get chilly in the early hours). Just open your eyes wide and don't try and focus on anything in particular. Enjoy the stars and the stillness and nature's fireworks show. Maybe not as fancy as a 4th of July, but still magical!!
This is the Southern Delta Aquarids meteor shower which show up from mid July to mid August each year with peak activity this year on July 28 & 29. This shower gets its name because most of the meteors ("shooting stars") seem to come from the constellation Aquarius, near one of its brightest stars, Delta Aquarii. This is considered to be a "strong" shower, which means there are likely to be a relatively high number of observable meteors. What this means is that under "dark sky" locations where there is not too much light pollution, you could potentially see 15-20 meteors per hour with a possible peak of 60.
If you don't want to get up early, you can start viewing after midnight and by 2AM you should be guaranteed to see some streaks in the sky. The best viewing times are in the pre-dawn hours away from the glow of city lights. Look halfway between the South and Southeast, at between 30 and 60 degrees above the horizon, and if conditions are right you will see meteors fanning out through all compass points from east to north to west with fewer seen heading southward.
The best way of viewing meteors is actually with your peripheral (side) vision as the eye's retina is more sensitive to low light conditions this way. So relax in a good recliner, get your blanket and a hot beverage (even on warm days it can get chilly in the early hours). Just open your eyes wide and don't try and focus on anything in particular. Enjoy the stars and the stillness and nature's fireworks show. Maybe not as fancy as a 4th of July, but still magical!!
Happy Viewing!
Wednesday, July 18, 2007
The Sky at Night (1)
At our backyard bar-b-que, some guests were having an argument, and I was asked to resolve it.
Guest 1, pointing to the south, "Okay, which planet is that one? I say Venus."
Guest 2, "It's not a planet, it's a star:"
Me, "Yes it's a planet, either Saturn or Jupiter."
Guest 1, "No, it's too bright, must be Venus."
Guest 3, "Oh, oh, you question the "professor"? You're gonna learn something now!"
Me (ignoring the teasing), "Okay, which planet is closer to the Sun, Venus or Earth?"
Guest 1, "Venus".
Me, "So, Venus will always be close to the Sun in the sky, either right after sundown or just before sunrise."
Guest 1, "Makes sense. So which planet is it?"
Me, "Not sure. Let me look it up." I go online to Tonight's Sky. "It's Jupiter."
Guest 2, "Are you sure it's not a star?"
Me, "It's not a star. I'll prove it to you." I get out the telescope (Meade ETX-70AT Autostar). The sun had gone down, the wind had subsided, it was clear at the moment, although not really dark. The object was just above the roof of a neighbor's house and I was able to get it in focus fairly quickly. "Take a look."
Guest 1, "Okay, I see a white dot. Why is this Jupiter?"
Me, "See the little dots on either side, along the middle of the big dot?"
Guest 1, "Yeah, there are two of them."
Me, "If you look closer, you should see 3, one is really close in. Those are some of Jupiter's moons."
Guest 2, "What are you looking at?"
Guest 1, "Yeah I see 3. Those are Jupiter's moons? How many does it have?"
Me, "Over 60 so far. But only a few are visible with a small telescope. Here, let me put in a stronger lens."
Guest 1, "Honey, come look at this. Jupiter's moons!"
Guest 3, "Told you you'd learn something!"
With the new lens we could actually see 4 moons, just like Gallileo did in 1610. All our guests and their kids got a chance to look through the telescope. And the kids brought their friends who were playing on the street. And we all talked about how amazing it was.
And it was. Though I've seen the same view many times, each time is still amazing and exciting. We were fortunate with the weather and the timing. Often you cannot see all 4 moons as they are in front of or behind the planet. Or the weather is not clear enough. Or Jupiter comes up too late or too early to make it easy to set up the scope. But we were lucky. Maybe you will be too. For the next 2 weeks or so, look a little to the south for the "first star", about 30 degrees above the horizon. With clear skies and a powerful pair of binoculars, or a small telescope, you should be able to see Jupiter and if you are lucky, one or more of its moons.
Happy viewing!
Guest 1, pointing to the south, "Okay, which planet is that one? I say Venus."
Guest 2, "It's not a planet, it's a star:"
Me, "Yes it's a planet, either Saturn or Jupiter."
Guest 1, "No, it's too bright, must be Venus."
Guest 3, "Oh, oh, you question the "professor"? You're gonna learn something now!"
Me (ignoring the teasing), "Okay, which planet is closer to the Sun, Venus or Earth?"
Guest 1, "Venus".
Me, "So, Venus will always be close to the Sun in the sky, either right after sundown or just before sunrise."
Guest 1, "Makes sense. So which planet is it?"
Me, "Not sure. Let me look it up." I go online to Tonight's Sky. "It's Jupiter."
Guest 2, "Are you sure it's not a star?"
Me, "It's not a star. I'll prove it to you." I get out the telescope (Meade ETX-70AT Autostar). The sun had gone down, the wind had subsided, it was clear at the moment, although not really dark. The object was just above the roof of a neighbor's house and I was able to get it in focus fairly quickly. "Take a look."
Guest 1, "Okay, I see a white dot. Why is this Jupiter?"
Me, "See the little dots on either side, along the middle of the big dot?"
Guest 1, "Yeah, there are two of them."
Me, "If you look closer, you should see 3, one is really close in. Those are some of Jupiter's moons."
Guest 2, "What are you looking at?"
Guest 1, "Yeah I see 3. Those are Jupiter's moons? How many does it have?"
Me, "Over 60 so far. But only a few are visible with a small telescope. Here, let me put in a stronger lens."
Guest 1, "Honey, come look at this. Jupiter's moons!"
Guest 3, "Told you you'd learn something!"
With the new lens we could actually see 4 moons, just like Gallileo did in 1610. All our guests and their kids got a chance to look through the telescope. And the kids brought their friends who were playing on the street. And we all talked about how amazing it was.
And it was. Though I've seen the same view many times, each time is still amazing and exciting. We were fortunate with the weather and the timing. Often you cannot see all 4 moons as they are in front of or behind the planet. Or the weather is not clear enough. Or Jupiter comes up too late or too early to make it easy to set up the scope. But we were lucky. Maybe you will be too. For the next 2 weeks or so, look a little to the south for the "first star", about 30 degrees above the horizon. With clear skies and a powerful pair of binoculars, or a small telescope, you should be able to see Jupiter and if you are lucky, one or more of its moons.
Happy viewing!
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