From an early-morning lunar eclipse “blood moon” to an evening blue “super” moon, Wednesday, Jan. 31, will be a day full of lunar excitement.
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Start the day with a lunar eclipse
On the morning of Jan. 31, the full moon will glide through Earth's shadow, creating a total lunar eclipse. The eclipse will start in the Phoenix area at 3:51 a.m., and the moon will be in total eclipse from 5:51 to 7:07 a.m. The moon will set at 7:28 a.m.
“There are often two or three lunar eclipses a year,” said School of Earth and Space Exploration astrophysicist Patrick Young. “Lunar eclipses can range from the moon barely passing through Earth’s shadow to going right through the darkest part. Wednesday’s eclipse will be closer to passing through the darkest part of our planet’s shadow.”
And it's expected to be a bloody good show.
“A total lunar eclipse is often called a ‘blood moon’ because the moon appears to turn red,” said Aaron Boyd, research analyst for ASU’s Lunar Reconnaissance Orbiter Camera (LROC). “What you’re actually seeing is the light from all of Earth’s sunrises and sunsets falling on the surface of the Moon. When this red light strikes the lunar surface, the moon shines red."
Unlike a solar eclipse, you can safely look at a lunar eclipse with the naked eye — no special equipment needed. Binoculars or a telescope can be used to view the lunar surface and the eclipse in greater detail.
Representatives from the Lunar Reconnaissance Orbiter Camera (LROC) will have a telescope set up from 5:30 to 7:30 a.m. on the ASU Tempe campus on the top floor (west side) of the Apache Boulevard parking structure, located on the corner of Apache Boulevard and Normal Avenue. The telescope will be set up to look at the moon, Jupiter and Mars.
“A total lunar eclipse is a beautiful sight to see,” Young said. “It’s also a way to learn about how the solar system moves, to observe the mechanics of the universe, and it gives us a reason to look up.”
How a spacecraft orbiting the Moon prepares for an eclipse
The Lunar Reconnaissance Orbiter (LRO) is a NASA mission launched in 2009 to identify sites on the moon with high scientific value, favorable terrain and the environment necessary for safe future robotic and human lunar missions. The ASU-led Lunar Reconnaissance Orbiter Camera (LROC) is a system of three cameras on the LRO capturing images of the lunar surface.
The LROC team is making special preparations for Wednesday’s total lunar eclipse, but not to take pictures.
Instead, because LRO is a solar-powered spacecraft, the eclipse will cut off its solar power supply and plunge it into cold darkness. To prepare, the ground team will be doing as much as it can before the eclipse to warm the spacecraft. Just before the spacecraft enters the eclipse, all non-essential systems will be shut down to conserve power so the spacecraft’s batteries can be devoted to warming the instruments and keeping them in working order.
“I always worry when there is a lunar eclipse,” said Mark Robinson, of the School of Earth and Space Exploration and LROC’s principal investigator. “Normally, LRO has to run off its battery for a little less than an hour, but during a total lunar eclipse the spacecraft does not see the sun for over three hours.”
LRO has been operating since 2009, so, like an older mobile phone battery, the spacecraft’s battery doesn’t have the same capacity to charge as it used to. “We are turning everything off in the spacecraft that we can in order to survive,” Boyd said.
End the day with a blue super moon
Wednesday will also bring us a “blue moon,” so called when a full moon occurs twice in a month. Since the moon goes from new to full and back again in 28 days, a longer month will sometimes have two full moons, one at the very beginning of the month and one at the very end. Although not exactly rare, they occur only every 2.7 years on average, hence the common saying, “once in a blue moon.”
The moon will also be a “closest super moon” on Wednesday. Because of their respective orbits, the moon will be closer to Earth, and Earth will be closer to the sun, so the moon will be receiving more light from the sun and it will be closer to us.
“We should expect to see that the moon appears about 14 percent larger during a super moon,” Boyd said.
To celebrate the blue “super” moon, the School of Earth and Space Exploration’s LROC team will host a Blue Super Moon event on Jan. 31 on the ASU Tempe campus. Experts from LROC, the AstroDevils and the School of Earth and Space Exploration will be on hand to answer questions about the moon, including how the solar-powered LRO spacecraft kept its instruments warm during the eclipse.
The Blue Super Moon event, which is open to the public, starts outside of the school’s main building (ISTB4) on the Tempe campus at moonrise, 6:27 p.m. Telescopes will be set up for optimal moon viewing (weather permitting) by the ASU AstroDevils. Moon posters, postcards and LROC mission stickers will be provided to all attendees.
At 7:30 p.m., you can catch a 3-D show, “The Moon Revealed” at the Marston Exploration Theater. This live-narrated 3-D show provides an unparalleled look at the moon in 3-D, including historical missions to the moon and the latest research from LROC.
Tickets for the 3-D show may be purchased in advance online or at the box office prior to the show. Mention code “BlueMoon” and receive a special discounted rate of $5 per ticket, either in person or online.
Top photo: The moon taken with 36 nearly complete wide-angle camera mosaics by the Lunar Reconnaissance Orbiter Camera team at ASU. Photo by NASA/GSFC/Arizona State University