A Cool Idea to Catch Up With an Interstellar Visitor

Poor, dim-witted humanity.

We used to think we were the center of everything. That wasn’t that long ago, and even though we’ve made tremendous advancements in our understanding of our situation here in space, we still have huge blind spots.

For one, we’re only now waking up to the reality of interstellar objects passing through our Solar System.

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Interstellar Comet 2I/Borisov Appears to Have Broken in Half

In 2019, amateur astronomer Gennadiy Borisov discovered a comet, which now bears his name. There’s a long history of amateur astronomers discovering comets, as they approach our inner Solar System on their elongated orbits. But this one was different: it was moving much too fast to be gravitationally bound to the Sun.

It was an interstellar comet. And now, it looks like it has split into two chunks.

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The heliosphere looks a lot weirder than we originally thought

Every second of every day, our sun spits out a stream of tiny high-energy particles, known as the solar wind. This wind blows throughout the solar system, extending far beyond the orbits of the planets and out into interstellar space.

But the farther from the sun the wind gets, the more slowly it streams, changing from the raging torrent that the inner planets experience (strong enough to cause the aurora) into nothing more than an annoying drizzle. And far enough away – about twice the orbit of Neptune – it meets and mingles with all the random bits of energetic junk just floating around amongst the stars.

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New Study Shows the Earth and Moon are not so Similar After All

According to the most widely-accepted theory, the Moon formed roughly 4.5 billion years ago when a Mars-sized object named Theia collided with Earth (aka. the Giant Impact Hypothesis). This impact threw up considerable amounts of debris which gradually coalesced to form Earth’s only natural satellite. One of the most compelling proofs for this theory is the fact that the Earth and the Moon are remarkably similar in terms of composition.

However, previous studies involving computer simulations have shown that if the Moon were created by a giant impact, it should have retained more material from the impactor itself. But according to a new study conducted by a team from the University of New Mexico, it is possible that the Earth and the Moon are not as similar as previously thought.

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Satellites Watched Mercury’s Transit From Space, Confirming That Yes, the Sun Has At Least One Planet

Do you wonder how astronomers find all those exoplanets orbiting stars in distant solar systems?

Mostly they use the transit method. When a planet travels in between its star and an observer, the light from the star dims. That’s called a transit. If astronomers watch a planet transit its star a few times, they can confirm its orbital period. They can also start to understand other things about the planet, like its mass and density.

The planet Mercury just transited the Sun, giving us all an up close look at transits.

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A NASA Panel Says We Don’t Need to be so Careful About Infecting Other Worlds

It’s time to update the rules. That’s the conclusion of a panel that examined NASA’s rules for planetary protection. It was smart, at the dawn of the space age, to think about how we might inadvertently pollute other worlds with Earthly microbes as we explore the Solar System. But now that we know a lot more than we did back then, the rules don’t fit.

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Rosetta Saw Collapsing Cliffs and Other Changes on 67P During its Mission

It seems that comet 67P/Churyumov–Gerasimenko is not the stoic, unchanging Solar System traveller that it might seem to be. Scientists working through the vast warehouse of images from the Rosetta spacecraft have discovered there’s lots going on on 67P. Among the activity are collapsing cliffs and bouncing boulders.

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Metallic Asteroids Might Have Had Volcanoes Erupting Molten Iron. That’s So Metal

Remember the asteroid Psyche? It’s the largest known asteroid in the asteroid belt between Mars and Jupiter. It’s been in the news because of its unusual properties, and because NASA plans to launch a mission to Psyche in 2022.

Psyche, aka 16 Psyche, is unusual because it’s quite different from other asteroids. Psyche appears to be the remnant, exposed nickel-iron core of an early planet. Because of that, Psyche is a building block left over from the early Solar System, when planets were still forming. It’s like a planet without a crust.

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