Frost on Mars

The Mars Phoenix Lander has observed water frost on a Martian morning. Water vapor in the atmosphere had frozen during the night, and as the sun rose through the morning the frost evaporated. I'm surprised that there is enough water in the Martian atmosphere for a visible amount of water frost to form.

Water frost on Mars

Seeing a photograph of water frost got me wondering what it would look like when the Phoenix lander starts being encased in carbon dioxide ice when the winter starts. And will we see even more water frost as time goes by? Is the Phoenix mission going to last enough for us to even see carbon dioxide frost, or even the entire surface around the landing site being covered by a white layer of carbon dioxide ice?

Water in moon rocks

Our Moon is known for being a very dry place with no water at all, except possibly for some ice at the poles. And researchers have not been able to find any in the lunar rocks brought back from the Apollo missions until recently. However, according to Scientific American, they have now found trace amounts of water in lunar volcanic glasses brought back from the Apollo missions.

Previous attempts at finding water in the lunar rocks failed because researchers could not tell whether any water detected was truly part of the original lunar material or whether they were Earth-based contaminants. Using secondary ion mass spectrometry, researchers were finally able to discover that lunar volcanic glasses contained water in a concentration of about 46 parts per million. Based on this, they estimate that the Moon once must have had water concentrations of 750 parts per million in its mantle.

It shouldn't have come as a surprise, since the Moon probably formed from the impact of a Mars-sized body with the Earth, so plenty of water must have been mixed in the impact debris. But after thinking of the Moon as a completely dry body for a long time, the news of the discovery had an impact.

The image of lunar volcanic glasses retrieved by Apollo 17 is courtesy of NASA.

Water from Mercury

Surface of Mercury as seen from MESSENGER during its January 2008 flyby

While a direct and close-up observation of water on Mars is exciting, we already knew about the existence of water on Mars for quite awhile. But the solar system can still throw us big surprises. One might think that the planet Mercury would not have any water, being so close to the Sun so that any water would have been blasted away by the solar wind. But when the MESSENGER spacecraft made its initial flyby of Mercury this January, water was exactly what it detected in its atmosphere.

MESSENGER is to orbit Mercury starting from 2011, but to save fuel it approaches Mercury numerous times to reduce its speed using Mercury's gravitational pull. During its flyby in January, it flew through Mercury's thin atmosphere and collected particles from the atmosphere. While it found the expected amount of elements such as sodium, potassium, and calcium, it also found significant amounts of water among the particles, which was a complete surprise.

The MESSENGER spacecraft has already made several big discoveries in just a single flyby this January, the others being the fact that volcanism is responsible for the smooth plains of Mercury and that many of the planet's features are due to its shrinking iron core. With just one flyby resulting in significant scientific results, including the unexpected detection of water in Mercury's atmosphere, I think we can look forward to when MESSENGER really starts its mission in 2011 when it goes into orbit around the planet. Even bigger surprises are sure to come.

The image of the surface of Mercury as MESSENGER receded from the planet in its January 2008 flyby is courtesy of NASA.