Category Archives: Orion

astronomy, Orion, planet-forming scenarios, planetary science, radio astronomy, star formation

Orion’s Pebbled Pathway to Stars and Planets

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Radio Astronomy Reveals a Long and Winding Road in Space

Radio/optical composite of the Orion Molecular Cloud Complex showing the OMC-2/3 star-forming filament. GBT data is shown in orange. Uncommonly large dust grains there may kick-start planet formation. Credit: S. Schnee, et al.; B. Saxton, B. Kent (NRAO/AUI/NSF); We acknowledge the use of NASA’s SkyView Facility located at NASA Goddard Space Flight Center.

Wow!  Check out this latest image of the Orion Nebula!

Just when you think astronomy can’t get any cooler, something like this comes out: radio astronomers using the Green Bank Telescope (a radio telescope in West Virginia) have found filaments of star-forming gas near the Orion Nebula. Embedded in those filaments are what they think could be large grains of rocky material, the building blocks of planets.

If this discovery is held up through further observations, it would be the first time large particles — perhaps the size of a Lego-type building block — have been detected in such a dense super-nurturing star- and planet-forming nursery. Prior to this, regions of star birth were understood to be thick with dust-sized grains.  The existence of larger grains could change the dynamic of planet formation in this and other regions where larger particles exist.

Scott Schnee, an astronomer at the National Radio Astronomy Observatory (NRAO) and lead on the team doing the work, pointed out that the availability of large-enough (pebble or Lego-sized) planetary building blocks would encourage the formation of planets around newborn stars in the region. “If you want to build a house, it’s best to start with bricks rather than gravel,” he said, implying that it would lead to faster building rates than normal.

Planet formation, similar to building a house, needs material to get started. Most planet nurseries start out with grains of material perhaps no larger than dust specks or maybe sand bits. Over time, those materials stick together to form larger and larger planetesimals, which collide to form planets. If you can start with bigger pieces, that might shorten the planet formation time.

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Stargazing in February

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It CAN Be Done!

The first month of the year is behind us now, leaving 11 more months of sky sights to check out. February for many northern hemisphere observers is still the winter season, so of course you have to dress warmly unless you live in relative sunny climes. For southern hemisphere viewers it’s late summer, so the dress code’s a little different. No matter what you wear, though, there ARE some great sky sights to check out.  I outline a few of them in my monthly video called Our Night Sky, produced for Astrocast.TV. You watch it here.

A chart view of Orion, showing Betelgeuse in the shoulder of the giant. The three belt stars run through the middle, and just below them is the Orion Nebula starbirth region. Courtesy Zwergelstern on Wikimedia Commons.

I always come back to Orion for my sky gazing this time of year. It’s just a gorgeous star pattern.  What I like most about Orion: it provides a lot of interesting stuff to look at. There’s Betelgeuse, for example. It’s a red supergiant star in his shoulder, and it’s likely to pop off as a supernova anytime (well, “anytime” is relative — it could be in the next million years).

Notice the three stars across Orion’s middle. Just beneath them lies a spectacular star birth region called the Orion Nebula. It’s about 1,500 light-years away from us and it just blazes with hot young stars, set among clouds of gas and dust that are still forming stars.

I’ve been stargazing since I was a kid. I didn’t always know what I was looking at, but over time (and using star charts and taking a few astronomy classes and teaching in the planetarium) I got to know the sky pretty well. You don’t have to do all that to explore the sky. You can start very simply: take it one constellation at a time.  Look at it with your naked eye, then scan it with binoculars or a small telescope.  Chances are, you’ll find something cool and interesting to check out each time you look.

People often ask me what star charts they should get. I always recommend they check out Sky&Telescope.com or Astronomy.com. Those two sites (and their associated magazines) have very useful star charts that you can customize for your location. If you have an iPhone or an iPad, you can get a wonderful app called Starmap. (Disclosure: I’m working on a project for these guys, but I was using their sky maps (free of charge on their site) long before they contacted me to work with them.)  I also very much like Skymaps, which provides both northern and southern hemisphere charts.  I also wrote about some good astronomy books and apps just before Christmas — check them out  here and here if you’re looking for some more extensive, tree-based information about where to look during your sky gazing sessions.  Now, get out there and check out the sky!  (Just be sure and dress for the weather!)