When the Sun wil betray us
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Ice fiesta on Vesta?
Though generally thought to be quite dry, roughly half of the giant asteroid Vesta is expected to be so cold and to receive so little sunlight that water ice could have survived there for billions of years, according to the first published models of Vesta’s average global temperatures and illumination by the sun.
“Near the north and south poles, the conditions appear to be favorable for water ice to exist beneath the surface,” says Timothy Stubbs of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore County. Stubbs and Yongli Wang of the Goddard Planetary Heliophysics Institute at the University of Maryland published the models in the January 2012 issue of the journal Icarus. The models are based on information from telescopes including NASA’s Hubble Space Telescope. …(NASA)
Into the real world
NASA’s chief climate scientist James E. Hansen built his career studying Earth’s atmosphere and modeling humans’ potential impacts on climate. Then he realized that laboratory work wasn’t enough. Hansen never thought his decision to study atmospheric models would lead to his arrest. But there he was in handcuffs this summer, protesting at the White House against a pipeline that would carry crude oil from Alberta’s oil sands to the Gulf of Mexico.
It wasn’t the first arrest, either. Hansen, who has directed NASA’s Goddard Institute for Space Studies for 31 years, earned the sobriquet “father of global warming” after testifying before Congress in 1988 on the dangers of global warming. He appeared again in 1989. Then he quietly returned to his work, turning aside television and media requests for the next 15 years because, as he said, “you have no time to do the science if you’re talking to the media.” … (Universe Today)
Huzzah!
Today is the first day of the rest of my life. 51 years ago it was the first day of my life. It was a Monday also.
To continue a tradition I always look up the evening sky at the moment I was born. Mars and the Moon were high in the sky, in first quarter (51% to be precise). Now Jupiter is high in the sky and the Moon is new (actually 11 hours and 46 minutes after new Moon).
Below you can see both vistas. Click on them to see a larger version.
Up to the next birthday.
Monday, January 23, 20.15 (in 1961)
Monday, January 23, 20.15 (today)
Clean Up Earth’s Orbital Ghetto
Space debris includes discarded man-made objects such as defunct satellites, which have exceeded their life times or malfunctioned, and rockets that have finished their missions.
Space debris is inevitably created during satellite operations. For example, solar array paddles are folded and tied with wires for launch, and when the paddles were deployed, the wire was discarded into space. Camera lens caps were also thrown away in space.
A vast number of fragments are created from either explosions or collisions. Most space debris is a result of the break-ups caused by these events. Satellites are launched on rockets that carry extra amounts of fuel. After a rocket has injected its satellite into the orbit, its remaining fuel can trigger an explosion, if its fuel tanks are heated by sunlight and highly pressurized. Satellites also carry fuel so they can keep the right orbit and attitude, so explosions can also happen if the fuel tanks of post-mission satellites get heated enough by sunlight. There have been about 200 such explosions confirmed to date.
And today there are also more collisions, as Earth’s orbit gets more crowded. The collision probability is becoming higher and higher. …. (JAXA)
Into the Jupiter Abyss with Juno
An unlikely ally
Generally, solar flares are bad news for stuff orbiting the Earth. The impact of intense solar radiation on sensitive electronics can render the most sophisticated space technologies useless. Also, heating and expansion of the Earth’s upper atmosphere by peaking solar activity can increase drag on satellites, slowing them down, causing them to drop from orbit.
How could this negative situation be turned into a positive? What’s bad for operational satellites has the wonderful side effect of helping mankind with an increasingly pressing problem: the specter of space junk…. (Discovery)
