It’s official: water ice on Mars!
Posted: July 18, 2008 Filed under: Astronomy, Chemistry, Environment, Technology Leave a comment »Big news from NASA as scientists announced that the Phoenix mission had found water ice on Mars.
The evidence is a pair of photographs taken 4 days apart showing small chunks of ice disappearing – by sublimation – from the bottom of the small trench dug by a robotic arm. The comparison photos below show the chunks in question before and after sublimation at the bottom left of the picture.
Amazing stuff. When the chunks were first observed, they were hypothesised to be either water ice or salt. However, salt crystals won’t sublime under the conditions at the landing site. Water will.
BTW, the announcement came first ( June 20) on the Phoenix lander’s tweet! And folks have been saying Twitter is of no use…
Lost and found in the universe
Posted: May 21, 2008 Filed under: Astronomy, Pure research Leave a comment »Space may not be so empty after all. Astronomers are reporting that they have discovered material forming a ‘backbone’ for the universe, along which the galaxies we can see are arrayed, and that this is a store house of regular baryonic matter (protons, neutrons & electrons making up familiar atoms).
Again, the way this study has been done is really clever. The scientists were looking at the light coming from stars and studying the way it was changed as it travelled towards Earth. Along the way, baryonic matter absorbed light at predicatble wavelengths in fairly consistent ways allowing the observers to draw very solid conclusions about the nature and quantity of the ‘stuff’ filling up space.
BTW, don’t confuse this stuff with dark matter. Baryons are attracted to the gravitational influence of dark matter to form the ‘cosmic web’ but that’s a whole ‘nother story…
(illustrations from Space Telescope Science Institute, STSI, at NASA)
Age of the universe
Posted: March 11, 2008 Filed under: Astronomy Leave a comment »Careful observations, by the Wilkinson Microwave Anisotropy Probe over 3 years, of microwave radiation left over from the Big Bang have produced the most accurate information yet about the age of the Universe: 13.73 billion years, with an error margin of just 120 million years.
The diagram below, courtesy of NASA, gives an idea of the sequence of events during that time.
We really can’t hope to comprehend these sorts of time scales, but the evidence makes for interesting conjecture and a great narrative!
The Bad Astronomy Blog has a great overview of the universe’s story thus far.
Martian slip’n'slide
Posted: March 5, 2008 Filed under: Astronomy, Pure research Leave a comment »A lucky snap from the high resolution cameras onboard the Mars Reconnaissance Orbiter has shown NASA scientists an avalanche in progress on the surface of the planet near its north pole.
While the cause is unknown, the result is spectacular:
Subsequent orbits of the planet will allow a closer look at the area to see how the terrain responds and to study the composition of the fallen material; already conclusions about the amount of ice involved have been drawn.
Wouldn’t you love to see this in person? One day perhaps…
Moon shot
Posted: February 29, 2008 Filed under: Astronomy Leave a comment »The search for water (in the form of ice) under the surface of the moon is moving into a new stage.
NASA plans to crash two probes into the southern polar regions of the moon in an effort to find ice underground. A previous probe detected hydrogen in those craters, and scientists now want to see if that hydrogen is bound up as water.
For a long time, there has been a hope that water, discovered on the moon, would remove one of the main problems with establishing a long-term settlement there. Transporting water from Earth to a colony on the moon would be a prohibitively expensive. Much better to get it once you are there.
What happens in 7.6 billion years time?
Posted: February 25, 2008 Filed under: Astronomy, Environment 1 Comment »Well, according to these articles arising from work done at Sussex Uni our sun will have swollen to a size greater than the Earth’s current orbit and swallowed it up.
No need to worry, though: life will already be gone long before then as the approaching surface of the sun boils the oceans away and blasts it into space on solar winds.
On the up side, however, the sun will lose mass during this process and its gravitational influence on our planet will be diminished. It is possible that this phenomenon, together with ‘nudges’ from passing asteroids, might allow the Earth to move further away from the sun – to increase the radius of its own orbit – and escape being engulfed.
But there still won’t be any oceans.
Moon, cubed
Posted: February 14, 2008 Filed under: Astronomy Leave a comment »The Cassini-Huygens mission to Saturn & Titan, launched in 1997, has sent some fantastic photos home but this one of Epimetheus, one of Saturn’s 60 known moons, bears some special examination.
At just 116km diameter Epimetheus never became ball-shaped under its own gravitational pull when it formed. The result is a roughly cubic shape, probably the result of several large meteor or comet impacts over the life of the solar system. A real oddity.
Lucy in the sky
Posted: February 4, 2008 Filed under: Astronomy Leave a comment »Aliens might be the first to legally download music by the Beatles.
While you can’t purchase the Fab Four’s music from iTunes or any other online store yet, NASA is beaming their tunes into space.
Using radar telescopes and scanning arrays usually reserved for listening to the skies or communicating with satellites, NASA will beam the Beatles song Across the Universe today, and invite others to do the same.
Anything listening at the other end – orbiting the target star Polaris – will have a long time to wait for the download: it is 431 light years away!
Target: Earth?
Posted: February 2, 2008 Filed under: Astronomy Leave a comment »Its been 100 years since a meteorite exploded over Tunguska in Siberia, devastating vast tracts of (thankfully) sparsely populated forest and tundra.
But what would happen if the same event occurred today? Just last week astronomers watched a small asteroid – called TU24 – pass through space just outside the Moon’s orbit.
And in 2029 a 400 metre long chunk of rock called Apophis will pass between the Earth and the Moon – to return in 2036 with a fairly high likelihood of impacting our planet in an explosion 4 to 8 times more powerful than the 1883 eruption of Krakatoa.
