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Many Moons

In Moons by Brian Koberlein3 Comments

Of all the moons in the solar system, ours is unique. It has surface composition similar to Earth’s, pointing to a common origin, and it’s unusually large to be orbiting such a small planet. Just how such a large moon came to orbit Earth remains a bit of a mystery. With a similar composition to Earth, it couldn’t have been captured by Earth’s gravity, and the Earth and Moon didn’t likely form at the same time from the primordial gas and dust of the solar system. So the dominant theory is that of a single large impact. Early in its history, Earth was struck by a Mars-sized object, sometimes called Theia. A combination of material from Earth and Theia coalesced to form the Moon. Read More

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National Observatory

In ACEAP by Brian Koberlein0 Comments

Kitt Peak is the oldest national observatory in the United States. It was founded in 1958, when the National Science Foundation signed a lease with the Tohono O’odham Nation, upon whose land the observatory resides. Read More

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Surface Of The Sun

In Sun by Brian Koberlein2 Comments

This image might not look like much, but it’s actually an amazing step forward for solar astronomy. It captures the image of a large sunspot not in visible light, but in microwaves. Read More

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Violet Sky

In Light by Brian Koberlein2 Comments

Why is the sky blue? It’s a common question asked by children, and the simple answer is that blue light is scattered by our atmosphere more than red light, hence the blue sky. That’s basically true, but then why don’t we see a violet sky?Read More

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The Last Eclipse

In Earth by Brian Koberlein0 Comments

One thing 2017 has going for it is a total solar eclipse. Such eclipses are relatively common, but they often occur in hard to reach areas where not many people live. But the eclipse this Fall will wander across the central US, making it highly accessible. Such solar eclipses are only possible thanks to the favorable orbital geometries of the Sun, Moon and Earth, but its those same geometries that mean such total solar eclipses will eventually come to an end. Read More

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Deep Field Black Holes

In Black Holes by Brian Koberlein5 Comments

At the heart of most galaxies lies a supermassive black hole. How such black holes came to be is a matter of some debate. Did black holes form first, and galaxies later formed around them (bottom up model), or did galaxies form first, and only later did their cores collapse into a black hole (top down model). To answer this question we need to have a good understanding of when these black holes started to form. A new ultra-deep x-ray image is helping to answer these questions.Read More

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Antimatter Astronomy

In Cosmology by Brian Koberlein16 Comments

In astronomy we study distant galaxies by the light they emit. Just as the stars of a galaxy glow bright from the heat of their fusing cores, so too does much of the gas and dust at different wavelengths. The pattern of wavelengths we observe tells us much about a galaxy, because atoms and molecules emit specific patterns of light. Their optical fingerprint tells us the chemical composition of stars and galaxies, among other things. It’s generally thought that distant galaxies are made of matter, just like our own solar system, but recently it’s been demonstrated that anti-hydrogen emits the same type of light as regular hydrogen. In principle, a galaxy of antimatter would emit the same type of light as a similar galaxy of matter, so how do we know that a distant galaxy really is made of matter? Read More

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Evidence Of Absence

In Dark Matter by Brian Koberlein7 Comments

Gamma rays are the most energetic forms of light in the Universe. They’re generated by a variety of sources, from the heated material surrounding supermassive black holes, to the supernova explosions of dying stars. But some have theorized they might also be produced by dark matter. Read More

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Winter Wonderland

In Science by Brian Koberlein2 Comments

It’s winter in the northern hemisphere. That fact, combined with the arctic blast that’s reddening many cheeks in North America, means that many of us will enjoy a white Christmas. Since it’s a time to be thankful, here’s five reasons you should thank astrophysics for this year’s Winter wonderland. Read More