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Category : Roaming the Cosmos

Roaming the Cosmos – Trappist-1

The arrangement of planets we see in the solar system is just one of many, many possibilities. The grand expanse of the universe holds a tremendous variety of planetary systems and we need not go far to find something unusual. Trappist-1 is a small dwarf star, not much bigger than the planet Jupiter, located about forty light years away in the constellation Aquarius – a small distance in comparison to the 100,000 light-year breadth of the Milky Way. Revolving around […]

Roaming the Cosmos – Vega

Fourteen thousand years ago, the North Star wasn’t the North Star. The night sky in the northern hemisphere currently turns around Polaris, the brightest star in the Little Dipper. But that changes, ever so slowly, because the Earth is not a perfect sphere. Its spin gives it a slight bulge at the equator. Gravitational forces from both sun and moon apply a gentle torque to this bulge, causing the pole to move in a circle. This movement is called axial […]

Roaming the Cosmos – Proxima Centauri B

As we move farther away from the sun, our journey gets colder and colder. If we want to find warmth and light again, it will be around distant suns. Every star has a habitable zone — a range of orbits in which a planet could have liquid water on its surface. Our system has one planet in the habitable zone. But how common is this? How many stars must we pass in order to find one with a planet in […]

Roaming the Cosmos – Haumea

Astrophysicists currently surveying the outer edges of our solar system estimate that there are thousands of dwarf planets, though only five have been researched enough to be recognized officially by the International Astronomical Union: Ceres, Pluto, Haumea, Makemake, and Eris. Ceres is the only dwarf planet in the inner solar system. It’s a part of the asteroid belt. Indeed, about one-third of the mass in the entire asteroid belt is concentrated in Ceres. The distant Eris is the most massive […]

Roaming the Cosmos – Uhlanga Regio, Triton

It’s currently late summer in the southern hemisphere of Triton, and it will be for a while. Seasons on Triton, Neptune’s largest moon, last over 40 years, with each pole spending 80 years in sunlight followed by 80 years of darkness. So where is the best place to spend a (very, very, very) extended summer vacation on Triton? We suggest Uhlanga, the southern polar region of Triton, named after the marsh from which humanity was born in Zulu mythology. There […]

Roaming the Cosmos – Verona Rupes, Miranda

[Update: Recent images of Charon, a moon of Pluto, from the New Horizons mission indicate that Charon may be home to the tallest cliff in the solar system. See: A ‘Super Grand Canyon’ on Pluto’s Moon Charon] In the woods near my childhood home there was a cliff. I suppose it is more accurate to say there is a cliff — cliffs don’t move much on a scale of decades — but ‘was’ seems more appropriate because the actual size […]

Roaming the Cosmos – Xanadu, Titan

Titan is appropriately named. The great ringed gas giant Saturn has sixty-two moons. But ninety-six percent of the mass of those moons is found in one object: Titan. At 5,150 km across, it’s diameter is greater than the planet Mercury. It is three-quarters the size of Mars and fifty percent larger than Earth’s moon, Luna. Titan is the only place in the solar system – apart from Earth – where you’ll find liquid on the surface and it is the […]

Roaming the Cosmos – The Caves of 87 Sylvia, Asteroid Belt

Hidden among millions of massive objects in the Asteroid Belt is a rare astronomical gem: an asteroid with two moons of its own. Asteroid 87 Sylvia, named for the Roman mythical mother of twins Remus and Romulus, is an oblong rock averaging 286 kilometers in diameter. It’s twin moons are, of course, named Remus and Romulus. Sylvia is an exceptionally low density asteroid. At least a quarter and probably more than half of its interior is empty space. At about […]

Roaming the Cosmos – Alpha Regio, Venus

Veiled in gold, Earth’s sister planet was once a tantalizing mystery. What lay below those clouds? Oceans? Jungles? Many imagined a lush garden world. They were quite wrong. The mean surface temperature is 735 K (462 C, 863 F). Atmospheric pressure is ninety-two times that of Earth. The evocative descriptor “hellish” is often used to describe Venus. But it is so very beautiful. Eighty percent of the planet’s surface consists of overlapping lava plains, with hundreds and hundreds and hundreds […]

Roaming the Cosmos – Noctis Labytinthus, Valles Marineris, Mars

Earth’s solar system contains hidden wonders for the enterprising cosmic adventurer to discover. For example, if you were to visit your near neighbor Mars, the more obvious spot is Olympus Mons. Olympus Mons is obvious because Olympus Mons is big. Ridiculously big. The colossal mountain stands over three times as tall as Mount Everest, Earth’s highest point above sea level. As its slope only rises at an average of 5°, the entire mountain covers roughly 300,000 square kilometers. Olympus Mons […]