The Incredible Shrinking Moon

(Simply stated, the moon is shrinking.

According to a recent scientific study, including images taken by NASA's Lunar Reconnaissance Orbiter, or the LRO, the lunar surface has revealed a series of geologic faults that weren't seen before.
These small faults, which are caused by internal cooling of the moon, have been discovered all over the moon, said Thomas Watters, a planetary geologist at the Center for Earth and Planetary Studies of the Smithsonian National Air and Space Museum in Washington, D.C.

"We know it's shrinking by looking at these landforms called lobate scarps that kind of look like stairsteps in the landscape," Watters told AOL News. "They're caused by thrust faults, which are generated when the lunar crust material is pushed together and pushed up, forming a cliff or scarp."

What excites scientists is that the LRO camera's high-resolution images reveal details down to a half meter to 2 meters per pixel resolution, and this is how Watters and his colleagues have been able to detect the scarps all over the moon.

But the biggest discovery about these structures, Watters added, points to the fact that the moon is still active.

"These faults could be so young that they may be indicating very, very recent tectonic and, therefore, geologic activity on the moon. One of the general conceptions out there is that the moon is this geologically dead body, and that's really not the case," he said.

Exactly how much lunar shrinkage are we talking about? And since the moon is directly involved with the rising and falling of global sea levels, should we be getting into panic mode down here on Earth at the idea of a smaller moon?

"Overall, it's only about 100 meters in the past billion years, so it's not a whole lot of contraction -- it's not something you're ever going to notice from Earth," Watters said. "But because the scarps are widespread, they definitely indicate the moon's crust has been shrinking.

"The mass of the moon hasn't changed; the overall size of the moon has changed slightly and become slightly smaller. Therefore, the tidal effects on Earth are exactly the same."

These lunar scarp structures were initially discovered in images photographed by several Apollo missions during the 1970s. But the LRO cameras now reveal how widespread the scarps are on the moon.

In the cosmic scheme of things, Watters wants to reassure us that there's no cause for alarm to Earthlings.

"No, absolutely not. The moon is not shrinking away. There's no fear that if you don't get out there and see the moon today, in the next cycle, it won't be there."

The complete details of Watters' study can be found in today's edition of the journal Science.

Amazingly Fast Eruption on the Sun Photographed

One of the fastest big solar eruptions in years has been observed streaking away from the sun at more than 2.2 million mph by two NASA spacecraft.

The flare occurred Aug. 1 and created a massive sun eruption called a coronal mass ejection that struck Earth's magnetic field Tuesday, creating dazzling aurora displays. NASA's twin STEREO spacecraft recorded the eruption and beamed images of the sun storm back to Earth. [Photo of the sun eruption.]

The material ejected from the sun was seen speeding toward Earth at more than 1,000 kilometers per second, or just over 2.2 million mph (3.6 million kph). Another wave from the event was expected to hit Earth's magnetic field on Wednesday. NASA's two STEREO spacecraft, which monitor the sun's weather in 3-D, also recorded a video of the sun eruption.

"These kinds of eruptions are one of the first signs that the sun is waking up and heading toward another solar maximum expected in the 2013 time frame," NASA officials said in a statement. The sun goes through a regular 11-year activity cycle. The last solar maximum occurred in 2001 and its recent extreme solar minimum was particularly weak and long-lasting, the space agency added.

Coronal mass ejections are eruptions of charged particles from the sun that stream out over several hours. They can contain several billion tons of plasma and expand away from the sun at speeds of up to 1 million mph (1.6 million kph). At such speeds, they can cross the 93 million-mile (150 million-km) gulf between the Earth and sun in two to four days.

The material belched from the sun during the Aug. 1 flare is not expected to cause any disturbances on Earth other than creating spectacular auroras. Auroras are created when charged particles are caught by Earth's magnetic field and interact with the atmosphere above the poles.

The Aug. 1 solar flare was a moderate C-class flare. The coronal mass ejection it set off created a strong so-called geomagnetic storm that lasted nearly 12 hours – enough time for auroras to spread from Europe to North America, NASA officials said in a statement.

Stronger solar storms could cause adverse impacts to space-based assets and technological infrastructure on Earth.

Solar Tsunami? Look Up Tonight for a Grand Show

A solar storm could make tonight a great night for stargazing.

The sun's surface erupted early Sunday and sent tons of plasma into space, according to the Harvard-Smithsonian Center for Astrophysics. It's headed toward Earth, which could be in for a beautiful light show.

"This eruption is directed right at us, and is expected to get here early in the day on August 4th," astronomer Leon Golub of the astrophysics center, said in a statement. "It's the first major Earth-directed eruption in quite some time."

Some publications have dubbed it a "solar tsunami."

Solar Dynamics Observatory / NASA

A pair of huge eruptions from the sun, such as this one spotted in April, has created a mass of plasma that that is now racing toward the earth.

The eruption, called a coronal mass ejection, was captured by a NASA camera. Depending on its path, it could make the northern lights, or aurora borealis, visible tonight.

"When a coronal mass ejection reaches Earth, it interacts with our planet's magnetic field, potentially creating a geomagnetic storm," Golub said. Solar particles "collide with atoms of nitrogen and oxygen in the atmosphere, which then glow like miniature neon signs."

Residents of the northern U.S. and other nations should look to the north tonight and early Wednesday to see rippling "curtains" of green and red light, Golub said. While aurorae can usually only be seen at high latitudes, they also can be on display at more southern points during a geomagnetic storm, Golub said.
Cities, because of their bright lights, aren't good places to see the show, Golub told The Boston Globe.
Scientists will get an idea of when the lights can be seen after the eruption passes by a satellite, the Globe said. They will know about an hour ahead of time.