Moon Rocks Contain Water

The general agreement about the Moon had been before that it was completely dry. No traces of water at all. And detailed research of the Moon rocks brought back by the Apollo astronauts seemed to completely confirm this agreement for more than 30 years. But new discoveries have showed that the Moon does contain a little bit  of water.

Image: Some of the volcanic glasses brought to Earth by the Apollo astronauts. Credit: NASA

The Formation of the Moon

The most widely accepted theory about the creation of the Moon involves an impact between a Mars-sized body, called Theia, and the Earth about 4.5 billion years ago. This impact is believed to have launched enough material into space which gradually coalesced into the Moon.

During this formation, most scientists believe that any water existing on the developing moon would have been vaporized into space. Because of this, many think that water has not existed at all on the Earth's satellite. However, this idea may be changed by a research team from Brown University, whose findings were published in the July 10 issue of Nature.

The Research Team

Assistant professor of geological sciences at Brown University, Alberto Saal, has led a team that has discovered evidence for water on the Moon. Analyzing the lunar volcanic glasses, small beads collected by the Apollo 15 mission, they have found minute traces of water. Previously, these rocks were thoroughly searched, but evidence of water did not appear.

But Saal and his team decided to use a technique developed by Erik Hauri from the Carnegie Institution for Science: secondary mass ion spectrometry. Earlier techniques could detect water in the lunar rocks to about 50 ppm (parts per million), but this technique could detect to about 5 ppm. This led to the detection of water in the glass beads.

Water in the Beads

The glass beads were created from small droplets of magma that has come from fire fountains more than 3 billion years ago. The team believes that almost all of the water vapor in the magma disappeared as gas into space right after it came out.

They studied the beads to make sure that they originated from the fire fountains and not fromt he impact of Theia. Saal's team also had to check that the beads were not contaminated by outside factors, like hydrogen from the solar wind.

After the team analyzed the beads, they found that they contained 46 ppm of water. Knowing that most of the water had evaporated during the eruption of the fire fountains, they estimated that pre-eruption magma contained up to 750 ppm of water.

Origin of the Water

So this finding generates a new question: Where did the water on the Moon come from? There are right now two possible answers to this question. Water either did not completely vaporize into space during the formation of the Moon, or came later from the outside, such as from meteorites. This new discovery certainly has sparked new interest in the existing Moon rocks that were brought by the Apollo astronauts to Earth.

Red Stripe in Space

Image: NASA/ESA

So what exactly is that red stripe in the picture? The picture is one of the latest from the Hubble Space Telescope, and the main focus of the image is a red trail of gas. This gas is part of the remnant of a supernova that took place in our galaxy, and lies 6,850 light years away from Earth. So what supernova caused this?

SN 1006 took place in 1006 C.E. (A.D.) between April 30 and May 1. It had the brightest

 apparent magnitude (brightness viewed on Earth) of any stellar event known! The event has been described by many civilizations, particularly the Chinese and the Arabic, which provide us with detailed descriptions of the explosion as it appeared on Earth. Today, this red band is a part of what is left from the mighty supernova. The image on the right shows the shell of the supernova remnant and to what part of the shell the above image belongs to (outlined). Click on the image to view a larger size.

Find out more about:

• The Hubble Space Telescope Image (HubbleSite)
• SN 1006 (Wikipedia)

Space Week 2008

Image: Discovery Communications

It's Space Week on the Science Channel again, like last year. It starts today, July 6, at 9 PM E/P on the Science Channel and will last until July 11. Shows celebrating space will be shown during this time on the Science Channel.

Pluto, a Plutoid

Pluto with its moons, Charon, S/2005 P1, and S/2005 P2
Image: NASA/ESA

About two years ago, the International Astronomical Union (IAU) made a big decision. There are going to be eight planets, and Pluto was not one. For Pluto, and also for Ceres and Eris, a new category was created. Pluto, Ceres, and Eris are now considered dwarf planets, a round celestial body orbiting the sun which has not cleared the area around its orbit. In addition,

 dwarf planets cannot be satellites. However, on June 11, the IAU has made another decision.

Pluto is now also considered a plutoid. By the IAU's definition: "Plutoids are celestial bodies in orbit around the Sun at a semimajor axis greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit." Basically plutoids are dwarf planets that are outside the orbit of Neptune. This currently includes Pluto and Eris, but the IAU expects more planets to become plutoids in the future. There are already numerous objects that are candidates to become plutoids. However, this new categorization has not come without controversy.

The old decision to remove the planet status from Pluto was very cont

roversial, and many believe this new decision is just creating more disagreement. Some think that this is just creating more confusion, by introducing another term in the already big list of existing terms for the same outer solar system objects.

So, I am offering a question to you, the reader. Do you support the plutoid term? Vote on the poll on the sidebar at right. The poll will close on August 1, 2008, so vote now.

Update, Poll Results: With a total of six votes in the poll, three people supported the Plutoid and Dwarf Planet terms, while three other people preferred the original nine planets.