astronomy

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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The Mars/Moon Hoax Rears its Ugly Head

Well, the hysterical claims are starting up yet again. Yes, it’s the annual Mars/Moon madness again. Only this time, the folks claiming that the Moon and Mars will be the SAME SIZE OMG!!! NEVER AGAIN IN THIS CENTURY!!!! are claiming that on August 27th, 2014, we’ll be treated to a view of the Moon AND Mars both the same size in the sky.  The stories are accompanied with an image that implies they’ll be *thisclose* in the sky.  The whole idea is so screwed up it’s not even close to reality.   But, before I get to work dismantling the latest flight of fancy about this subject, the good news is that there is something neat to see in the sky that night (and indeed, for the next couple of weeks).  I’ll talk about that in a minute (below the jump).

Mars and Saturn appear close together as dots of light in the August 27th, 2014 post-sunset sky. The moon is a very slim crescent close to the horizon.

Mars and Saturn appear close together as dots of light in the August 27th, 2014 post-sunset sky. The moon is a very slim crescent close to the horizon. (Click to get a bigger version.)

Here’s a star chart that I made using Stellarium for the period of time just a few minutes after sunset on the 27th. This shows the sky with indicators for where the Moon and Mars will be. They are roughly 45 degrees apart — nowhere near each other, as it turns out.  So, that immediately puts the lie to the images I’ve seen showing two Full Moons next to each other (apparently one of them is supposed to be Mars). The insets show about how these objects will really look. The Moon will be a very young crescent (NOT FULL, as is shown in some of the graphics I’ve seen). Mars and Saturn will appear as dot-shaped  objects in the twilight. As it get darker, they’ll look brighter (since we won’t be contending with the twilight glow), but by that time, the Moon will have set. The chart doesn’t lie. You can go to Stellarium, download the free program, run it and see for yourself. It’s easy to do. Where did this huge misunderstanding come from?

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