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Caitlin: If you’ve ever wanted to get up-close and personal with the Moon, you might want to look up this Monday, because the moon will look larger and brighter than it has for decades. The full moon on November 14th will be the largest supermoon since 1948 – almost 70 years ago!

Supermoons happen between four and six times a year, whenever the full moon happens around the same time as the closest point in its orbit, also known as its perigee. But this supermoon is special, because the moon will be the closest it’s been to Earth since that supermoon back in 1948.

The moon’s orbit is an ellipse, not a perfect circle, so that’s part of the reason it’s closer to Earth on some nights than on others. But the moon’s perigee also changes a little from orbit to orbit, because it’s influenced by the gravitational pull of the Sun. On average, the Moon orbits about 384,400 kilometers away, and its closest point to Earth is usually somewhere between 357,000 and 370,000 kilometers away. But sometimes the perigee dips below 357,000 kilometers.

And Monday will be the biggest dip in decades, to 356,511 kilometers. Plus, the full moon is happening within about two hours of that extra-close perigee. Since the moon will be so close, it will look up to 14% larger and 30% brighter than a full Moon that’s at the farthest point in its orbit.

The Moon won’t be this close to Earth again until November 2034, when there’ll be another extra-big supermoon. The moon will be exactly full at 1:52 PM GMT, which translates to the early morning in the Americas and the afternoon in Europe. But the moon will be extra large and bright on both Sunday and Monday night, too. If you’re in Asia or Australia, you’re in luck, since the moon will reach its peak on Monday night.

No matter where you are in the world, though, if there are clear skies, it’s probably worth looking up. While we’re watching the moon, the James Webb Space Telescope will be getting ready to observe the rest of the universe!

Webb has been in development for 20 years now, and it’s finally in the home stretch. Last week, the telescope part of Webb was finished, which includes the mirrors and all of the scientific instruments. So basically all that’s left to do before launch is some rigorous flight testing! Once it’s launched, the telescope will mainly view the universe in infrared, the wavelength associated with heat. That will give us a whole new perspective, since the Hubble Space Telescope’s range doesn’t include several kinds of infrared light.

Webb is also more sensitive than the Hubble, so it’ll be able to give us lots of extra detail. But even though construction on the telescope is over, it has to pass a whole bunch of tests before it can start its mission in space. Engineers have already completed a pre-test to confirm that the telescope’s optics are working — which they are! And because rocket launches are loud and pretty violent, they’ll now put the telescope through sound and vibration tests to make sure it won’t be damaged on the way into orbit.

If it survives these tests without damage, next up are cryogenic tests to make sure it can handle the super cold temperatures of space. Finally, the telescope will be shipped to California, where it’ll be attached to the rest of the spacecraft: the sunshield to protect it from the heat of the sun, and the propulsion and communication systems. After the last few tests wrap up, the completed spacecraft will be shipped to French Guiana to launch aboard the European Ariane 5 rocket. If everything goes as planned, the James Webb Space Telescope will launch in October 2018!

With Webb, we’re hoping to learn more about a lot of different things, like the oldest galaxies in the universe, other star systems, and even worlds closer to home, like Jupiter’s moon Europa. So whether you’re watching for the greatest supermoon in almost 70 years or waiting for the world’s best space telescope, you can expect a beautiful view of space coming your way soon.

Thank you for watching this episode of SciShow Space News, and thanks especially to our patrons on Patreon who help make this show possible. If you want to help us keep making episodes like this, just go to Patreon.com/SciShow. And don’t forget to go to YouTube.com/scishowspace and subscribe!