25 January 2012
NASA recently published a wonderful view of five Saturnian moons, acquired by the Saturn-orbiting Cassini spacecraft. Rhea (1,528 km across), Saturn’s second largest moon, dominates the picture, while Saturn’s magnificent rings are visible nearly edge-on, below Rhea. (The names of most planetary moons come from mythologies.)
22 January 2012
NASA recently published an amazing image (Fig. 1), showing the Moon, our only natural satellite, and the International Station (ISS), Earth’s largest artificial satellite, passing close to the Moon. This photograph, taken from Houston, Texas, records a magnificent alignment of Earth’s two largest satellites.
18 January 2012
NASA recently published a new image of an unusual cosmic view (Fig. 1), revealing the discovery of a new pulsar, a tiny, extremely dense stellar object, characterized by a very powerful magnetic field. The pulsar is located in a small nearby galaxy, known as the Small Magellanic Cloud, lying some 200,000 light years away from Earth. The pulsar discovery was made by combining data from NASA’s Chandra X-ray Observatory, a sophisticated satellite exploring the universe in X-rays, and the European Space Agency’s X-ray space observatory, XMM-Newton satellite.
15 January 2012
Astronomers using data from NASA's Kepler spacecraft have discovered the three smallest exoplanets ever spotted around a star beyond our Solar System. (Planets orbiting other stars are termed exoplanets, or extrasolar planets.) The exoplanets’ parent star is known as KOI-961. The three exoplanets are estimated to be smaller than Earth (12,756 km across) in size. The smallest of them is about the size of Mars (approximately 6,800 km across).
12 January 2012
NASA recently published a wonderful image (Fig. 1) of the night side of Earth, acquired by an astronaut, aboard the International Space Station (ISS), Earth’s largest artificial satellite, orbiting at an altitude of about 350 km. The image, obtained on 4 December 2011, shows the Iberian Peninsula and parts of North Africa and Western Europe.
08 January 2012
On 1 January 2012, NASA's GRAIL-B spacecraft, the second of the two Gravity Recovery And Interior Laboratory (GRAIL) spacecrafts, successfully entered orbit around the Moon. Its twin, the GRAIL-A spacecraft, entered Moon orbit on 31 December 2011. Working together, GRAIL-A and GRAIL-B will conduct an unprecedented study of the Moon. The mission’s prime object is to map the lunar gravitational field, and probe the internal structure of the Moon.
04 January 2012
In early June 2011, Chile’s Puyehue-Cordón Caulle Volcano erupted, spewing volcanic ash across the Southern Hemisphere, and forcing the evacuation of thousands of people. The ash cloud reached a height of 12,000 meters, on 4 June. In late December 2011, activity at the volcano had declined, but volcanic ash and steam were still erupting from the fissure that opened several months earlier.
01 January 2012
On 31 December 2011, NASA's Gravity Recovery And Interior Laboratory (GRAIL)-A spacecraft was successfully placed into orbit around the Moon. GRAIl-A’s lunar orbit is highly elongated, measuring 90 km by 8,363 km, and lasts approximately 11.5 hours to complete.
29 December 2011
On 13 December 2011, NASA's Dawn spacecraft reached its lowest orbit around giant asteroid Vesta (530 km across), the most massive asteroid, and relayed its most detailed images of Vesta’s surface. The images show numerous small craters and other terrains.
25 December 2011
NASA recently published a beautiful image of the bright Comet Lovejoy, taken by an astronaut, onboard the International Space Station (ISS). The image shows the comet shining over the night side of Earth, whose atmosphere glows in fascinating hues. The ISS is the largest spacecraft ever launched into space. It orbits Earth at an altitude of about 350 km.