Stay up late for a lunar treat Monday and watch the moon turn red. The occasion is a rare lunar eclipse, when Earth steps between its steady sidekick and the sun, blocking most of the light that makes it shine.
Over the next two years, the North Coast sky will host a four-part series of total lunar eclipses -- sometimes called a “Blood Moon” -- starting Monday.
Though lunar eclipses are quite common, Astronomers of Humboldt member Jeff Schmitt said this tetrad of eclipses is “kind of exciting.”
”When you end up with several in a row like this, it's sort of unusual,” Schmitt said.
The first lunar eclipse in the tetrad starts around 10 p.m. on the West Coast, with a total phase occurring from around midnight to 1:30 p.m. Tuesday.
”If you have a good imagination, it's kind of eerie,” said Richard Neuschaefer, an avid stargazer who serves on the board of the San Jose Astronomical Association.
But for NASA's Lunar Atmosphere and Dust Environment Explorer, or LADEE, the eclipse might be a curse. LADEE (pronounced laddie) is a vending-machine-sized spacecraft orbiting the moon that is collecting information about its sparse atmosphere. It's the first spacecraft designed and built at Mountain View's NASA Ames Research Center and the first to examine the moon's atmosphere since the Apollo missions 40 years ago.
Without the sun's warm rays, LADEE's instruments will chill and could dip below their operating capacities, said Butler Hine, the mission's project manager.
That wouldn't be disastrous, as LADEE has already given scientists many new insights into the composition of the moon's atmosphere. In fact, the mission could have ended earlier but benefited from a problem-free launch, said Rick Elphic, a LADEE project scientist.
”Lucky LADEE, we've had a lot of good things go our way,” Hine said. “What we're doing now is extra stuff.”
Now seven months into its mission, LADEE has uncovered previously unseen traces of neon, magnesium and titanium in the lunar atmosphere, Elphic said. These heavy metals are “hopping around the surface like bunnies,” he said, quoting another NASA scientist.
The moon is like a desert. When the sun hits, it rapidly heats the surface, causing even heavy metals to pop into their lighter, gaseous states -- and lift off for a bit. When the sun sets, the moon cools rapidly and those metals drop onto the surface, Elphic said.
LADEE is expected to crash into the moon around April 21, when its fuel will be exhausted, according to NASA. The eclipse isn't expected to affect its impact date, Hine said.
Scientists will take several months to unravel the data, which might hint at the source of the mysterious pre-sunrise glow Apollo astronauts reported while in orbit. But it doesn't look like LADEE was able to completely unravel the mystery, as the dust gathered so far isn't dense enough to produce a glow, Elphic said.
Back on Earth, tonight's eclipse kicks off a series of four lunar eclipses that astronomers call a tetrad. The next eclipse will happen in October.
An eclipse occurs only when the moon is full and doesn't happen every month because the moon's orbit is tilted.
The moon won't disappear completely because the Earth's atmosphere bends light with longer wavelengths, like red and orange, which then reflects off the moon.
NASA is hosting a live webchat to answer questions about the eclipse beginning at 9:45 p.m. at http://1.usa.gov/1sSZ271.
A live streaming viewing will also be available.