Kenneth Snyder, Flickr //  CC BY-NC-ND 2.0
Kenneth Snyder, Flickr // CC BY-NC-ND 2.0

Look Up! The Perseid Meteor Shower Peaks This Weekend

Kenneth Snyder, Flickr //  CC BY-NC-ND 2.0
Kenneth Snyder, Flickr // CC BY-NC-ND 2.0

Look up tonight and you’ll see streaks of light headed your way. The annual Perseid meteor shower has arrived, and if the skies are clear and light pollution low, you are in for quite a treat: This is easily the best meteor shower of the year. Those who stay up late (or wake really early) are virtually guaranteed to see something.

FROM SLAYER OF MEDUSA TO COMETARY DUST 

The Perseids are the result of a debris field left by the comet Swift-Tuttle. This is a Halley-type comet that orbits the Sun every 133 years. (Its highly eccentric orbit takes it far beyond Pluto in the meantime.) As the comet travels across the solar system, it leaves behind a trail of dust and sand-sized particles that, over the course of centuries and millennia, becomes an increasingly dense field. When the Earth's orbital path crosses this debris, the speed and force of our planet colliding into the comet's phantom particles vaporizes them. A distinctive "shooting star" is the result of energy released by a speck of cometary dust colliding with the atmosphere of a 3.7-octillion-mile celestial object—that would be Earth—moving at 67,000 miles per hour.

The Perseids get their name from the constellation from which they seem to originate: Perseus. Don’t limit yourself to staring at the celestial slayer of Medusa, however. (Though bonus points if you can actually find it.) Meteors will appear across the night sky. The shower was first formally "discovered" in 1835 by astronomer Adolphe Quételet, though it has been observed for millennia. Meteors near the shower’s peak are sometimes called the "tears of St. Lawrence," coinciding with the feast day of St. Lawrence of Rome.

KEEP AN EYE OUT FOR FIREBALLS

If you are in an area of low light pollution—that is, any remote area away from a city—you will be able to see between 30 and 40 meteors per hour this weekend. Believe it or not, that makes this a bad year for the Perseids shower, down from a possible 150 per hour. Many meteors will be obscured by the big bright Moon still riding high after reaching a full phase earlier this week.

To best experience a meteor shower, NASA recommends you dress for the lower temperatures that come at night and give your eyes a good 30 minutes to adjust to the darkness. Take a blanket outside, lay back, and take in the sky. Be on the lookout for fireballs, which are particularly bright meteors. (You'll know one when you see it.)

The best time to see the Perseids shower is between midnight and dawn on Saturday. If you miss the Perseids early Saturday morning due to bad weather (or just sleeping in), you can try again at the same time each early morning well into next week. If being outside just isn’t your thing, but astronomy is, you can also view the meteor shower online at Slooh, beginning at 8:00 p.m. EDT on Saturday. The Perseids are the perfect warmup for the main event later this month: a total solar eclipse over North America on August 21.

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iStock
Astronomers Discover 12 New Moons Around Jupiter
iStock
iStock

As the largest planet with the largest moon in our solar system, Jupiter is a body of record-setting proportions. The fifth planet from the Sun also boasts the most moons—and scientists just raised the count to 79.

A team of astronomers led by Scott S. Sheppard of the Carnegie Institute for Science confirmed the existence of 12 additional moons of Jupiter, 11 of which are “normal” outer moons, according to a statement from the institute. The outlier is being called an “oddball” for its bizarre orbit and diminutive size, which is about six-tenths of a mile in diameter.

The moons were first observed in the spring of 2017 while scientists looked for theoretical planet beyond Pluto, but several additional observations were needed to confirm that the celestial bodies were in fact orbiting around Jupiter. That process took a year.

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system,” Sheppard said in a statement.

Nine of the "normal" moons take about two years to orbit Jupiter in retrograde, or counter to the direction in which Jupiter spins. Scientists believe these moons are what’s left of three larger parent bodies that splintered in collisions with asteroids, comets, or other objects. The two other "normal" moons orbit in the prograde (same direction as Jupiter) and take less than a year to travel around the planet. They’re also thought to be chunks of a once-larger moon.

The oddball, on the other hand, is “more distant and more inclined” than the prograde moons. Although it orbits in prograde, it crosses the orbits of the retrograde moons, which could lead to some head-on collisions. The mass is believed to be Jupiter’s smallest moon, and scientists have suggested naming it Valetudo after the Roman goddess of health and hygiene, who happens to be the great-granddaughter of the god Jupiter.

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ESA/Herschel/SPIRE; M. W. L. Smith et al 2017
Look Closely—Every Point of Light in This Image Is a Galaxy
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017

Even if you stare closely at this seemingly grainy image, you might not be able to tell there’s anything to it besides visual noise. But it's not static—it's a sliver of the distant universe, and every little pinprick of light is a galaxy.

As Gizmodo reports, the image was produced by the European Space Agency’s Herschel Space Observatory, a space-based infrared telescope that was launched into orbit in 2009 and was decommissioned in 2013. Created by Herschel’s Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS), it looks out from our galaxy toward the North Galactic Pole, a point that lies perpendicular to the Milky Way's spiral near the constellation Coma Berenices.

A close-up of a view of distant galaxies taken by the Herschel Space Observatory
ESA/Herschel/SPIRE; M. W. L. Smith et al 2017

Each point of light comes from the heat of dust grains between different stars in a galaxy. These areas of dust gave off this radiation billions of years before reaching Herschel. Around 1000 of those pins of light belong to galaxies in the Coma Cluster (named for Coma Berenices), one of the densest clusters of galaxies in the known universe.

The longer you look at it, the smaller you’ll feel.

[h/t Gizmodo]

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