Friday, November 27, 2009

Observations

Date: 11/26/09
Time: 6:35-6:50
Location: Venice, FL
Conditions: Clear
Moon: Waxing Gibbous, high in the SouthEast
At 6:43, in the NNW, the ISS streaked across the sky for about two minutes. About 15 seconds after the ISS appeared, the Space Shuttle Atlantis transited the sky in the same direction. The two were at an angular separation of a few degrees. Both were very bright.

Date: 11/27/09
Time: 7:00-7:15
Location: Venice, FL
Conditions: some clouds, but bright stars still visible
Moon: Waxing Crescent, high in the SouthEast
At 7:06, the ISS again crossed the sky for about two minutes, this time in the WNW. The ISS was very bright.

Friday, November 20, 2009

Apod 2.3 Water Discovered in Moon Shadow

Last month, NASA sent a projectile to crash into the moon. The project was called the LCROSS mission. As part of the mission, one projectile crashed into the moon, followed by another that carried a detector. The detector's purpose was to see if there were signs of water on the moon. The impact occurred in a permanently shadowed crater on the moon's south pole. This past week, results from the chemical analysis of the dust plume showed clear evidence of water. The source of the water is unknown and is the topic of much debate. Whether from a small meteorite, a comet, or from primordial moon soil, the water is a mystery. The water is important because it could help us understand the history of the moon and could be the source of water that would allow astronauts to live on the moon for an extended period of time. NASA has plans to build a lunar colony somewhere between 2019 and 2024, so the presence of water is a big step in the fulfillment of these plans.

Friday, November 13, 2009

APOD 2.2 Stickney Crater

Stickney Crater is the largest crater on the tiny moon, Phobos, which orbits Mars. The crater, almost 9 kilometers from side to side, is almost half the diameter of Phobos itself. The crater is named after the wife, Chloe Angeline Stickney Hall, of Asaph Hall, who discovered Mars' two moons in 1887. The impact that formed this crater most likely cam very close to shattering the minuscule Martian satellite. This picture was captured by the HiRISE camera, which is part of the Mars Reconnaissance Orbiter. The orbiter passed within 6,000 kilometers of Phobos in March of 2008, which is when this picture was taken. The image is color-enhanced, and the presence of a light blue coloration on the crater's rim could mean that the surface is newly exposed. Streaks on the crater may indicate that, over time, material has slid down the crater walls and into the crater itself. Grooves along the surface are also visible, but their origin is still under question.

Friday, November 6, 2009

APOD 2.1 Blue Sun Bristling

This image of our sun was taken at the Hydrogen-Alpha wavelength of the spectrum. Hydrogen-Alpha's wavelength is 656 nm. The image was then inverted to appear blue. The sun is mostly composed of hot hydrogen gas. Taken at the Hydrogen-Alpha wavelength, the sun's chromosphere is easily visible. Spicules, thin long tubes about the length of the radius of the Earth that are composed of magnetically-confined hot gas, can also be seen bursting from the sun. Many people believe that the sun is on fire, but this is far from the truth. The sun has barely any Oxygen, which is essential to fire. In reality, the sun is just extremely hot gas. Energy from the sun is due to the fusion of hydrogen and helium in the core of the sun. Solar prominences can also be seen extending from the sun. Average size prominences extend many thousands of kilometers into space. However, in the picture they appear very tiny. This evidence shows how massive the sun really is. Sunspots, often visible on the sun, were not visible on the day that this photo was taken.