Comet Siding Spring won’t hit Mars on October 19 but it will come really, really close: 86,000 miles, or just a bit over 1/3 the distance between the Moon and Earth. That’s like having a bullet from a sniper positioned a mile away knock your hat off! (Given that you were the target of a military-class sniper, not sure why you would be. Is there something I don’t know about you?) And while it won’t get bright enough or close enough to Earth to become a spectacle in our night sky, exploration robots on and around Mars should be in for quite a show.
Earlier this month, as Siding Spring (aka C/2013 A1) passed within the orbit of Jupiter, the Hubble Space Telescope turned its gaze onto it and captured the image above showing the comet’s icy 12,000-mile-wide coma and, after some processing, what appear to be two strong jets spraying out of its as-yet-unseen nucleus. These observations — and more like them in the months to come — will help scientists determine Siding Spring’s motion and rotation rate and what sort of interaction Mars (and its resident robots) can expect from its ejected material this fall.
We all know that Saturn is encircled by a system of rings, and perhaps you also know about the fainter rings around Uranus, Jupiter, and Neptune. But today, ESO astronomers have revealed a surprising discovery: there are also rings surrounding the asteroid 10199 Chariklo, a small, distant world orbiting the Sun far beyond Saturn.
This makes 250-km-wide Chariklo the fifth world ever found to have rings, after the four planets mentioned previously, and, based on the observations, it could also even have its own moon.
“As well as the rings, it’s likely that Chariklo has at least one small moon still waiting to be discovered,” said Felipe Braga-Ribas of the Observatório Nacional/MCTI in Rio de Janeiro who planned the observation campaign and is lead author on the new paper.
“It’s as though you were locked in a room your whole life and then somebody opens a window.”
– Neil deGrasse Tyson
Do you remember your first telescope? Your first trip to a planetarium or observatory? Astrophysicist and Cosmos: a Spacetime Odyssey host Neil deGrasse Tyson does, and in this installment of NOVA’s Secret Life of Scientists and Engineers he shares his memories of seeing the Universe on the Hayden Planetarium’s big screens for the first time, and then receiving his own first telescope a couple of years later.
Obviously, they made quite the impression on young Neil.
“Saturn has rings! Oh my gosh the Moon has craters! Things you’ve heard about and read about, but to experience them yourself becomes a singular moment in your life. You are there in the Universe.”
We’ve known for quite some time now that lakes of liquid methane and ethane exist on the frigid surface of Saturn’s overcast moon Titan. While the sheer presence of large amounts of liquid on another world is fascinating, one thing that’s particularly intrigued scientists about these hydrocarbon lakes is their uncanny stillness — in many radar images they appear to be literally as smooth as glass, with no indication of movement or wave action of any sort. And although liquid methane isn’t water and probably behaves differently, with Titan’s substantial atmosphere it only makes sense that some sort of waves would get kicked up across lakes so vast, even from the most moderate seasonal breezes.
Now, a research team led by Jason Barnes of the University of Idaho has released findings showing what might be wave action — however small — captured by instruments aboard NASA’s Cassini spacecraft during several Titan flybys. And with the summer season approaching, this just might mean it’s “surf’s up” on Titan!
Our solar system is an active place, and that is no better illustrated than with these recent observations by the Hubble Space Telescope of asteroid P/2013 R3 breaking apart — and it’s not even disintegrating in Earth’s or any other planet’s atmosphere, but rather as it travels through space 480 million km away from the Sun!
Seen over the course of four months, the breakup of the 200,000-ton space rock is thought to not be the result of an impact event but rather the slight but unyielding force of solar illumination on an already compromised cluster of rubble, barely held together by its own gravity.
“This is a really bizarre thing to observe — we’ve never seen anything like it before,” says co-author Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany. “The break-up could have many different causes, but the Hubble observations are detailed enough that we can actually pinpoint the process responsible.”
Is Pluto a planet? A dwarf planet? A Kuiper Belt Object? All — or none — of the above?
Pluto has been a topic of scientific fascination since Clyde Tombaugh discovered it in February 1930, and then a topic of controversy after the IAU reclassified it as a dwarf planet in 2006. While conversations continue over Pluto’s planetary identity, at least one theme carried through the talks at the Pluto Science Conference in July 2013. See if you can figure out what it is in the video above! (Hint: it’s not difficult.)
NASA’s New Horizons mission will help us understand worlds at the planetary frontier by making the first reconnaissance of Pluto in July 2015. Read more about the mission here.
This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which I don’t think will ever happen.)
On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.
From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space. And Voyager was still a long ways off from reaching the “edge” of our solar system, the bubble of energy emitted by the Sun in which all of the planets, moons, and asteroids reside. In fact, Voyager 1 still has an expected five years to go before it crosses that boundary and truly enters interstellar space.*
“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”
– Carl Sagan