UARS has landed!

You're safe! UARS landed around midnight EST. The map above shows the path the satellite mostly likely took before it hit the ground early this morning.  NASA is still unsure about exactly where it hit, but speculates it was somewhere in the ocean along the green path above since no one reported seeing the crash.

UARS crash landing

 

 Images of UARS tumbling through the atmosphere

Have you heard on the news lately about a NASA satellite that's crashing to Earth this Friday? This object is called the Upper Atmosphere Research Satellite (UARS). It was put into orbit around Earth back in 1991, and spent 14 years studying Earth's ozone layer and our atmosphere in general. In 2005, the satellite was decommissioned because only half of the instruments on board were still functional, and the satellite had already lasted 11 years longer than it's original planned science mission. UARS had some fuel on board which it used as thrust to place itself on a decaying orbit, causing it to eventually fall back to Earth. The satellite will crash land on Earth this Friday afternoon, September 23rd, 2011. As UARS flies through the atmosphere, it is expected to burn up into as many as 26 different pieces ranging from a few pounds up to 400 lbs. These pieces will crash to Earth at speeds of up to 240mph, and are expected to be scattered over a 500mile wide area. NASA does not yet know exactly where the satellite will crash land, but they think it will land somewhere East of North America. If the satellite were to land in a populated area anywhere in the world, the estimated death rate is 1/3200. Hopefully UARS will land harmlessly in the middle of the ocean! Check out Spaceweather.com for more information on where UARS will land, and when you will be able to see it cross the sky. This fireball of a satellite should be visible on Friday even in broad daylight!

What is Space Like?

Ed White, the first American to perform a space walk. Image credit: NASA

You've learned so much about planets, moons, stars, galaxies, and all sorts of other astronomical objects, but do you have any idea about what space is really like? Outer space in general is very very cold. It's temperature is roughly 2.7 Kelvin, or -455 degrees F. Space is almost a perfect vacuum. A perfect vacuum is defined as an area of space with zero gas molecules. Outer space contains about 5 Hydrogen atoms per cubic meter. For comparison, on Earth there is about 10^25 gas molecules per cubic meter (that's a 1 with 25 zeros after it!). Space may be empty of molecules, but it's filled with light, most of which our eyes can't perceive. In the solar system, the sun emits all different types of light, from X-rays to microwaves. Earth's atmosphere blocks a majority of this light, but in outerspace there is nothing to block this light.  These are some of the many reasons why astronauts must wear space suits. With essentially no air to breathe, freezing temperatures, and deadly radiation, an astronaut would survive about 30 seconds if they took off their space suit. NASA has spent many years building spacecrafts and spacesuits that can withstand the harsh conditions in Space. They have done a pretty good job so far, but space is also very unpredictable. You never know what's going to happen out there!

The First Tatooine!

Anyone who has seen Star Wars remembers Tatooine, the home of Luke and Anakin Skywalker. Astronomers have found a real Tatooine! Well, they have found a planet with two suns at least. It's probably nothing like how George Lucas portrayed it though. 

Kepler 16-b is the first circumbinary planet ever discovered. It was first observed by the Kepler Space telescope on July 7th, 2011. The planet orbits a binary star system (Kepler-16) where one star is 70% the mass of the sun and the other is about 25%. In the system, the two stars orbit around each other, and the planet has an orbit surrounding the both of them . The planet is believed to be half rock and half gas,  roughly the size of Saturn, and orbits the stars in about 228 days. An interesting point of the discovery is that the three objects all orbit in the same plane. It's as if the stars and planets are balls on a table, orbiting each other but sitting on an imaginary flat surface. This supports the theory that this planet formed from a circumbinary disk; a disk of gas and dust that surrounded the binary star system as they were forming. Until now, astronomers weren't sure that the conditions were stable enough around a binary star system for a planet to form. The discovery of Kepler 16-b will help astronomers improve their star formation models, and maybe we will find more circumbinary planets in the future!

Image Credit: NASA