Category Archives: astronomy

'Casts, astrocast.tv, astronomy, the astronomer's universe

Mommy, Where Do Planets Come From?

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Taking a Closer Look

Over at Astrocast.tv I’ve been sharing some of the latest astronomy research in a four-minute-long (or so) segment called The Astronomer’s Universe. This month’s topic is planetary system formation and I give you a taste of what astronomers are looking at and what they’re learning as they observe the evidence of planetary formation.

I think people are quite fascinated with the topic for a number of reasons, but one that comes up over and over again is that it gives us insight into how our own Sun and planets formed.  By observing and delving deep into the regions where stars and planets are formed (using multiwavelength instruments — optical, infrared, ultraviolet, and even radio and x-ray) astronomers are starting to get a really good sense of the chemical and physical interactions that take place as clouds of gas and dust coalesce over millions and billions of years. We’ve known the general picture for a long time — that the coalescence results in rocky planets close to stars and gas/ice giants and frozen worlds and moons far away from the stars. And, we’ve known for quite a while that the raw materials for these formation scenarios come from stars that have died and expelled their masses to space.  But, the minute details of how chemicals combine with other ones, how particles stick together, how they stay together through the stormy youth and adolescence of their parent stars and their complex gravitational and magnetic environments, and a thousand other details — that’s all relatively recent research.  Those details mean a lot when it comes to understanding how our own solar system formed. And, how life arose within it (at least on Earth).

I invite you to watch here and then head over to Astrocast.tv (link above) for other enjoyable and fascinating segments about amateur astronomy, our green planet, and a look at space science news  by my fellow ‘Cast members Tavi Greiner, Bente Lilje Bye, and our host and old friend of mine, NASA Solar System Ambassador Greg Redfern. Special thanks to Rich Mathews, our executive producer, for all the hard work corraling us special correspondents and putting all the segments together!

amateur astronomy, astronomy, Jupiter

Another Once in a Lifetime Event

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Something Smacked Jupiter

An image of the large impact site on Jupiter, as captured by the NASA Infrared Telescope Facility on Mauna Kea. Click to embiggenify.
An image of the large impact site on Jupiter, as captured by the NASA Infrared Telescope Facility on Mauna Kea. Click to embiggenify.

Back when Comet Shoemaker-Levy 9 was headed in for a crash landing in Jupiter’s upper cloud decks, the event was often referred to as a “once in a lifetime” happening.  And, for most of us at that time, it was, since we hadn’t seen something like that before.

Not that stuff hasn’t been whanging into Jupiter regularly — it does, proably more than we think about. But, we just didn’t happen to see it often, and having a visible comet headed for a Jovian plopdown was (and probably is) rarer than having smaller pieces of space debris headed inbound for a rough landing.

How do astronomers know this spot was caused by an impact and not just a particularly nasty storm whirling up from below the cloud decks?  It’s all in the light being emitted by the region.  At infrared wavelengths in data and images taken by the NASA Infrared Telescope Facility on Mauna Kea, Hawai’i, the spot is quite bright, but it also shows evidence of an outburst of bright, upwelling particles from beneath the cloud tops, just like what you’d see if something smacked in and stirred up the region, sending materials up and out.

So, what came crashing down into the Jovian atmosphere? Could likely be a comet — and the evidence for that will be hidden in the signatures of chemicals (the ices in the comet) that were given off as the comet came slamming in.  It’s a busy time for astronomers who are watching this event unfold in real time — all spurred by the first discovery image posted by amateur astronomer Anthony Wesley a couple of days ago.

There’s another cool story here that I want to take a moment to discuss: how this discovery shows that amateur astronomers can and do (and have been for quite a while) been making valuable contributions to science, and occasionally they make discoveries that the big boys didn’t make!  This isn’t new — back in the 1990s, when I was in grad school, I worked with amateur observers around the world to chart comet orbits and apparitions across a range of comets. These folks, who often have observatories to rival good university facilities, were often sending me stunningly gorgeous and scientifically useful images of such objects as Comet Hale-Bopp, DeVico, and Hyakutake. They were valued partners in our research efforts.  And, that tradition continues with the discovery of this crash site on Jupiter, with ongoing observations of Mars, charts of variable star activity, and in many other areas of astronomy research.  Amateurs rule!