SJAA Ephemeris August 2012 | SJAA Home | Contents | Previous | Next

The Last Month in Astronomy


JUL-16-2012 • Curiosity Countdown • The car-sized Mars rover named Curiosity is set to land on Mars at 10:30 p.m. PDT on August 5. NASA is supporting a large range of programs and websites to increase the audience for this landing, the first of its kind. You can start at although some links on that page didn’t work as of July 16th. If you are watching on TV and you have DirecTV, note that NASA TV is now on channel 346.

JUL-11-2012 • Pluto and 5 moons • Astronomers using the Hubble Space Telescope have discovered a fifth moon around Pluto. The moon has not yet been given a name but it does have an official designation, S/2012 (134340) 1 but among friends it goes by “P5”. The previously found moon is still called P4. Better names will not be immediately forthcoming because astronomers aren’t sure if a sixth moon will make an appearance soon. So the names of Pluto’s moons are: Charon, Hydra, Nix, P4 and P5. The moons are in circular orbits and they seem stable. P5 might be as small as 10 kilometers.

JUL-09-2012 • Finding Planets • It is very difficult to directly image exoplanets. A new instrument in use at the Palomar Observatory is starting a 3 year survey to try to get this data. The instrument has a number of components. One is a chronograph - think of that as a high tech way of sticking your thumb up to block the sun and see Mercury next to it. That doesn’t work unless you have a total eclipse but this new instrument can do it thanks in part to adaptive optics. This component includes a mirror that can be deformed with an accuracy of 1 nanometers (a bacterium is about 100 nanometers) and make these changes 7 million times a second. This work is called Project 1640. It is a collaboration between the Museum of Natural History, Caltech, and JPL. According to Ben Oppenheimer (from the museum), “Once we can actually see these exoplanets, we can determine the colors they emit, the chemical compositions of their atmospheres, and even the physical characteristics of their surfaces. Ultimately, direct measurements, when conducted from space, can be used to better understand the origin of Earth and to look for signs of life in other worlds.”

JUL-04-2012 • Higgs boson • For those of you recently delivered to this planet, the Higgs boson has been detected. Two different experiments at the LHC have confirmed the discovery. What this means next is not clear. It might lead to a model that describes where dark matter came from and just how much of it there is. It might lead to some insight into dark energy. The results are still considered preliminary and more study will be needed. But the detection showing up just as expected is quite an accomplishment for physics. And more particles may be found at the LHC. As one researcher said, “this is A Higgs boson but we don’t know if it is THE Higgs boson.

JUN-28-2012 • Exoplanet Change • The Hubble Space Telescope and NASA’s Swift satellite have detected a massive change in the atmosphere of exoplanets HD 189733b, a Jupiter class planet only 3 million miles from its star. The hot Jupiter is more than 1000 degrees Celsius and its hydrogen is evaporating. It is estimated that 1000 tons of gas are leaving the atmosphere every second.

JUN-27-2012 • Odyssey pulls out a spare • The Mars Orbiter Odyssey is back in service after using a spare wheel, a reaction wheel to be exact. Spacecraft often use reaction wheels to maintain the proper attitude. A reaction wheel works by detecting when it needs to move a bit one way and it turns the opposite way. Hey, Newton was right, this works. Odyssey had a bum reaction wheel so it switched to a spare. That spare reaction wheel was doing nothing but taking up space for about 11 years. Now it has the Odyssey in good shape. By the way, Odyssey can also use thrusters to correct its attitude but that uses up propellant.

JUN-22-2012 • Lichen Likes Life • The journal Astrobiology is reporting on studies performed back in 2009. These studies took bacteria, seeds, lichen and algae and exposed them to space for more than 200 orbits. The items were brought back to Earth where the lichen are growing normally. Apparently some organisms can go into a dormant state even under the conditions involved in interplanetary travel. That adds support to the idea of panspermia - life spreading throughout the solar system.

JUN-11-2012 • Where Now Brown Star? • The WISE spacecraft has been looking for hard to detect brown dwarfs, stars that are too small to support nuclear fusion. The assumption has been that there must be a large number of these stars, probably as many brown dwarfs as there are regular stars. However, WISE has found only 33 brown dwarfs within 26 light-years. There are 211 successful stars in that same volume. So far no brown dwarfs have been found closer than Proxima Centauri and none are anticipated.


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