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Star Teacher January 2008
A Cosmic Boxing Match
A distant black hole in the middle of a galaxy is blasting its neighbor galaxy with radiation, scientists say. 3C321, a binary galaxy system light years away from our galaxy, is where this phenomenon is happening. A binary galaxy is a system in which two galaxies orbit around each other. In 3C321 the larger galaxy of the two has a huge black hole in its center. This black hole has been punching its orbiting neighbor with a huge jet of radiation.
The jet produces gamma and x-ray radiation, which have the potential to be lethal with high exposure. In addition to the radiation, the particles traveling at nearly the speed of light have devastating effects on the unlucky planets’ atmospheres. The two galaxies are close at only around 20,000 light years apart, approximately the distance from Earth to the center of the Milky Way. According to the research, the jet began to impact the galaxy approximately one million years ago.
The black hole was discovered by NASA’s Chandra X-ray Observatory, Hubble Space Telescope and the Spitzer Space Telescope, with help on the ground from the Very Large Array (VLA) in New Mexico, and the Multi-Element Radio Linked Inferferometer Network (MERLIN) in the United Kingdom.
This jet may not be all bad news for the galaxy that is being pummeled. Many new stars and planets could be created as a result of the energy and radiation. There is a possibility that it could help to create large numbers of new star systems.
For more information, please visit the Nasa press release.
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What's Happening In the Sky This January?
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Earth at perihelion (nearest the sun). Many people think that the earth is far away from the sun during winter, but this is not true! In January, our planet is actually as close as it will get to the sun this year. For more information about the Earth and its orbit see article below. |
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Quadrantid meteor shower occurs. This meteor shower peaks at two in the morning, but you can see meteors any time during the evening. This year is an especially good one for seeing the Quadrantids because the moon will not be very bright. |
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New moon: It will be so dark that it will be easier to see the stars, milky way, and maybe even meteors! |
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Full moon: The full moon in January is called the Full Wolf Moon. The wolf packs used to howl because they were hungry this time of year. |
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Mars begins eastward movement: Read more about Mars’s retrograde motion below! |
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Venus and Jupiter meet in the sky: Throughout January Venus and Jupiter will move closer and closer towards each other in the sky. On this day they finally meet! It will be a beautiful sight for anyone who gets up early and looks in the south east. |
Where Are the Viewable Planets?
| Venus |
Rises about three hours before sunrise in the southeast sky. This planet is the queen of the morning sky – it shines brighter than anything else (besides the moon). In the beginning of the month the crescent moon will pass close to Venus, making a beautiful sight. |
| Mars |
In the northeastern sky when the sun goes down. The red planet will not be as bright as it was in December, but it will be moving in an interesting way. Instead of moving west to east against the stars Mars will be in retrograde motion, moving from east to west. It will continue in this direction until the end of the month. |
| Jupiter |
Starts the month rising 25 minutes before sunrise. This head start will increase to almost two hours by the end of the month. Look for this planet in the constellation of Sagittarius in the southeast. Don’t miss its rendezvous with Venus at the end of the month! |
| Saturn |
Rises around 8 pm at the beginning of the month. Will grow brighter by the end of the month. Look for this ringed planet east of Regulus, the brightest star in the constellation Leo. Saturn is in retrograde right now, just like Mars, so over the month it will move closer and closer to Regulus. |
 
 
Mars's Strange Dance
If you were to look up at the night sky every night for a month what would you see? You would see the shape of the moon change and the stars move from east to west a little every night.
Those aren’t the only thing that would change, though. If you looked very closely you would find something that looks like a bright red star that moves in a funny way. One night this bright point of light would be in one place in the sky, while the next night it would appear to have moved a tiny bit. After a month it would be in a different part of the sky from where it started . This point of light isn’t a star. It’s a planet, from the Greek word "planete" meaning "moving one". Planets appear to move among -really against the background of- the fixed distant stars.
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See how retrograde motion works here! |
Normally planets seem to move from west to east across the sky. Every once in a while, though, a planet will seem to change direction and begin to move from east to west. After it does this for a while it will pause and then change directions again, going back to moving west to east. Scientists call this sort of movement retrograde motion. This January, the planet Mars is moving in this strange way. Mars is very bright from Maine right now, so it is easy to watch on clear nights.
Retrograde motion happens when a planet closer to the sun passes a planet that is farther away from the sun. Earth’s orbit is closer to the sun than Mars’s, which means Earth goes around the sun faster than Mars does. Every once in a while Earth catches up to Mars and passes it. This makes Mars appear to slow down and switch direction in the night sky. Once Earth has passed Mars our line of sight changes again, which causes Mars to appear to change direction again.
At the end of January Mars will be at the end of its retrograde motion and will be heading into the constellation of Gemini.
Click here for an activity about retrograde motion your students can do.
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Gemini is a zodiac constellation, which means it’s a constellation that the sun travels through in our sky. You can find it between Taurus (to the west) and Cancer (to the east). Gemini is easiest to spot by its two bright stars, Castor and Pollux. The name “Gemini” comes from the Latin word for twins. This makes sense because Gemini looks like two people! Castor and Pollux get their names from twins found in Greek mythology. |
Castor and Pollux were twin brothers with a big difference. Castor was a normal man, but Pollux was a god. The twins were very close and went on many adventures with each other. One day, though, the twins’ cousin became angry at Castor and killed him. Pollux was very sad at his brother’s death and wished to follow him into the underworld as well. Because he was a god, though, he could not die. The king of the gods, Zeus, was so moved by Pollux’s grief that he put both Castor and Pollux in the sky. Now the two twins are together forever in Gemini.
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We're Not As Far Away As We Think!
People in Maine know that January is a time for snow and cold. Spending time outdoors in the winter snow can be a lot of fun, but sometimes it feels like the sun is very far away this time of year. The funny thing is this: while we feel like the sun is very far away, we’re actually as close to it as we can get!
Our planet is always moving around the sun in its orbit. It doesn’t move in a circle, though. Instead, it moves in a shape called an ellipse. An ellipse is a shape that is not perfectly round like a circle is. Instead, it’s more like an oval. Different orbits have different ellipses. Some orbits are very stretched out and skinny. Other orbits are almost round. A worksheet activity for elementary students shows what an ellipse (orbit) might look like.
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Our Earth’s orbit is the kind that is almost round. The sun is not in the center of the Earth’s orbit. Instead it’s off to one side at a point called the focus. This means that the Earth is a little bit closer to the sun for part of the year than it is the rest of the time. When the Earth is as close to the sun as it can get we say it is at perihelion.
You can learn more about the ways the Earth and the planets move from the Jordan Planetarium show World in Motion and in this activity.
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Learn more about orbits and how they work here! |
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