When people in North America look up at the sky in the early morning hours of April 15, they can expect the moon to look a little different.
A total lunar eclipse is expected at this time, a phenomenon that occurs when the Earth, moon and sun are in perfect alignment, blanketing the moon in the Earth's shadow.
Although lunar eclipses happen multiple times in a year during a full moon, this eclipse will be a particularly unusual viewing opportunity for North America. Since the Earth's Western Hemisphere will be facing the moon during the eclipse, the continent will be in prime position to view it from start to finish. In addition, the eclipse will coincide with nighttime in North America. The entire continent won't be able to witness a full lunar eclipse in its entirety again until 2019.
"Sometimes they'll happen and you'll have to be somewhere else on Earth to see them," said Noah Petro, Lunar Reconnaissance Orbiter deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "Most [residents] of the continental United States will be able to see the whole thing."
For those who are awake to watch the eclipse, which is scheduled to begin around 2:00 a.m. EDT and last over three hours, Petro said there would be several changes people can witness. When the moon first enters the Earth's partial shadow, know as the penumbra, a dark shadow will begin creeping across the moon. This will give the illusion that the moon is changing phases in a matter of minutes instead of weeks.
"Eventually there will be a chunk of darkness eating the moon," Petro said.
At the eclipse's peak, around 3:45 a.m. EDT, the moon will enter the Earth's full shadow, the umbra. At this stage, the Earth's atmosphere will scatter the sun's red visible light, the same process that turns the sky red at sunset. As a result, the red light will reflect off the moon's surface, casting a reddish rust hue over it.
"It's a projection of all the Earth's sunsets and sunrises onto the moon," Petro said. "It's a very subtle effect, and if any part of the moon is illuminated in the sun, you can't really see it."
Although lunar eclipses are fairly common, Petro said they don't happen every month. Because the moon's orbit is tilted, it doesn't pass through the Earth's shadow each time it orbits the planet. This is the same reason why solar eclipses—which occur when the Earth passes through the moon's shadow—don't occur monthly.
Petro said lunar eclipses are a special treat people should take the opportunity to watch, even if it is at a late hour.
"They don't happen all the time, and the sky has to be clear," Petro said. "It really gives you a chance to look at the moon changing."
In addition to being a spectacle for North America residents, Petro said NASA's Lunar Reconnaissance Orbiter (LRO) team would be paying particular attention to this eclipse. The LRO mission, which is currently orbiting the moon, will be plunged into darkness for an extended period during the eclipse. Because the spacecraft's batteries need sunlight to charge, it will be forced to run without recharging longer than usual.
"The spacecraft will be going straight from the moon's shadow to the Earth's shadow while it orbits during the eclipse," Petro said.
While this isn't the first time LRO has orbited the moon during an eclipse, its past orbits have allowed it to pass into Earth's shadow only for a short period. This time, the spacecraft will have to pass through the complete shadow twice before the eclipse ends. However, Petro said the team expects the spacecraft to make it through the eclipse without a hitch.
"We're taking precautions to make sure everything is fine," Petro said. "We're turning off the instruments and will monitor the spacecraft every few hours when it's visible from Earth."
Although LRO would be forced to shut down its instruments for this eclipse, Petro said other lunar eclipses are a great opportunity for the mission to study how the lunar surface cools during these events, giving insight into the materials making up the surface.
While people watch the moon change in the sky April 15, the LRO team will be ready.
"For quite a while, people in LRO have been analyzing what's going to happen during this eclipse," Petro said. "We'll make sure the world knows LRO survived with no problems."
For more information about NASA's LRO mission, visit:
Rob Gutro | EurekAlert!
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Earth Sciences
05.12.2016 | Physics and Astronomy
05.12.2016 | Life Sciences