Quantcast

Super Blue Blood Full Moon: Here’s What You’ll See and Why on Jan. 31

Popular
As long as clouds don't get in the way, the view should be spectacular. NASA Goddard / CC BY

By Shannon Schmoll

During the early hours of Jan. 31, there will be a full moon, a total lunar eclipse, a blue moon and a supermoon—all at the same time. None of these things is really all that unusual by itself. What is rare is that they're happening all together on one day.

What Makes the Moon Look Full?

Like the earth, half the moon is illuminated by the sun at any one time. The moon orbits around the earth and as a result we see different amounts of the lit-up side.


The phases of the moon visible from Earth are related to its revolution around our planet. Orion 8, CC BY-SA

A full moon is when we see its entire lit-up side. This occurs every 29.5 days, when the moon is directly opposite the sun relative to the earth. Jan. 31 will be our next full moon in the lunar cycle.

What's a Lunar Eclipse?

The moon's orbit is tilted by about 5 degrees relative to the earth's orbit. So, most of the time the moon ends up a little above or below the path Earth follows as it revolves around the sun. But twice in each lunar cycle, the moon does cross into our planet's orbital plane.

A lunar eclipse happens when the moon is completely in the Earth's shadow. Tomruen, CC BY-SA

If that crossing corresponds to a full moon, the moon will pass into the earth's shadow, resulting in a total lunar eclipse. Since the moon needs to be behind the earth, relative to the sun, a lunar eclipse can only happen on a full moon.

To see the phenomenon, you need to be on the night side of the earth; this eclipse will be visible mostly in Asia, Australia, the Pacific and North America. But don't worry if you miss it—lunar eclipses happen on average a couple times a year. The next one visible in North America will be on Jan. 21, 2019.

A Blue Moon That Looks Red

When a lunar eclipse happens, the moon appears to darken as it moves into the earth's shadow, called the umbra. When the moon is all the way in shadow it doesn't go completely dark; instead, it looks red due to a process called Rayleigh scattering. The gas molecules of Earth's atmosphere scatter bluer wavelengths of light from the sun, while redder wavelengths pass straight through.

This is why we have blue skies and red sunrises and sunsets. When the sun is high in the sky, red light passes straight through to the ground while blue light is scattered in every direction, making it more likely to hit your eye when you look around. During a sunset, the angle of the sun is lower in the sky and that red light instead passes directly into your eyes while the blue light is scattered away from your line of sight.

A super blood moon tinted red by scattered light GSFC, CC BY

In the case of a lunar eclipse, the sunlight that makes it around Earth passes through our atmosphere and is refracted toward the moon. Blue light is filtered out, leaving the moon looking reddish during an eclipse.

On top of it all, the Jan. 31 full moon is also a considered a blue moon. There are two different definitions of blue moon. The first is any time a second full moon occurs in a single month. Since there are 29.5 days between two full moons, we usually only end up with one per month. With most months longer than 29.5 days, it occasionally works out that we have two full moons. We already had one on the first of this month and our second will be Jan. 31, making it a blue moon. With this definition our next blue moon is in March, leaving February with no full moon this year.

The second definition of a blue moon states it's the third moon in a season in which there are four moons, which happens about every 2.7 years. We'll only have three this winter, so the Jan. 31 full moon won't be blue by this definition. Stargazers will need to wait until May 18, 2019, for a blue moon that fits this older, original definition.

A Supersized Supermoon

Finally, to add the cherry on top, this will also be a supermoon. The moon's orbit is not perfectly circular, meaning its distance from Earth varies as it goes through one cycle. The closest point in its orbit is called the perigee. A full moon that happens near perigee is called a supermoon by some.

This happened with our full moon earlier this month on Jan. 1 and will again on Jan. 31.

Its proximity makes it seem a little bit bigger and brighter than usual, but that's the extent of its effects on Earth. The distinction is usually hard to notice unless you're looking at two pictures side by side.

Appearance of an 'average' moon versus a supermoon Marcoaliaslama, CC BY-SA

There are long traditions of giving different moons names. This being a bigger, brighter, reddish-looking blue moon, perhaps we should call the next full moon the super purple moon. The moon will not actually appear purple, nor will have it a cape—but Jan. 31 is a great time to gaze up and enjoy the night sky.

Reposted with permission from our media associate The Conversation.

EcoWatch Daily Newsletter

Tim P. Whitby / 21st Century Fox / Getty Images

The beauty products we put on our skin can have important consequences for our health. Just this March, the U.S. Food and Drug Administration (FDA) warned that some Claire's cosmetics had tested positive for asbestos. But the FDA could only issue a warning, not a recall, because current law does not empower the agency to do so.

Michelle Pfeiffer wants to change that.

The actress and Environmental Working Group (EWG) board member was spotted on Capitol Hill Thursday lobbying lawmakers on behalf of a bill that would increase oversight of the cosmetics industry, The Washington Post reported.

Read More Show Less
A protest march against the Line 3 pipeline in St. Paul, Minnesota on May 18, 2018. Fibonacci Blue / CC BY 2.0

By Collin Rees

We know that people power can stop dangerous fossil fuel projects like the proposed Line 3 tar sands oil pipeline in Minnesota, because we've proved it over and over again — and recently we've had two more big wins.

Read More Show Less
Sponsored
Scientists released a study showing that a million species are at risk for extinction, but it was largely ignored by the corporate news media. Danny Perez Photography / Flickr / CC

By Julia Conley

Scientists at the United Nations' intergovernmental body focusing on biodiversity sounded alarms earlier this month with its report on the looming potential extinction of one million species — but few heard their calls, according to a German newspaper report.

Read More Show Less
DoneGood

By Cullen Schwarz

Ethical shopping is a somewhat new phenomenon. We're far more familiar with the "tried and tested" methods of doing good, like donating our money or time.

Read More Show Less
Pixabay

Summer is fast approaching, which means it's time to stock up on sunscreen to ward off the harmful effects of sun exposure. Not all sunscreens are created equally, however.

Read More Show Less
Sponsored
Mark Wallheiser / Getty Images

The climate crisis is a major concern for American voters with nearly 40 percent reporting the issue will help determine how they cast their ballots in the upcoming 2020 presidential election, according to a report compiled by the Yale Program on Climate Change Communication.

Of more than 1,000 registered voters surveyed on global warming, climate and energy policies, as well as personal and collective action, 38 percent said that a candidate's position on climate change is "very important" when it comes to determining who will win their vote. Overall, democratic candidates are under more pressure to provide green solutions as part of their campaign promises with 64 percent of Democrat voters saying they prioritize the issue compared with just 34 percent of Independents and 12 percent of Republicans.

Read More Show Less
Flooding in Winfield, Missouri this month. Jonathan Rehg / Getty Images

President Donald Trump has agreed to sign a $19.1 billion disaster relief bill that will help Americans still recovering from the flooding, hurricanes and wildfires that have devastated parts of the country in the past two years. Senate Republicans said they struck a deal with the president to approve the measure, despite the fact that it did not include the funding he wanted for the U.S.-Mexican border, CNN reported.

"The U.S. Senate has just approved a 19 Billion Dollar Disaster Relief Bill, with my total approval. Great!" the president tweeted Thursday.

Read More Show Less
Reed Hoffmann / Getty Images

Violent tornadoes tore through Missouri Wednesday night, killing three and causing "extensive damage" to the state's capital of Jefferson City, The New York Times reported.

"There was a lot of devastation throughout the state," Governor Mike Parson said at a Thursday morning press conference, as NPR reported. "We were very fortunate last night that we didn't have more injuries than what we had, and we didn't have more fatalities across the state. But three is too many."

Read More Show Less