NASA Space Place – It Takes More Than Warm Porridge To Make A Goldilocks Zone

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in November, 2012.

By Diane K. Fisher

2013february2_spaceplaceThe “Goldilocks Zone” describes the region of a solar system that is just the right distance from the star to make a cozy, comfy home for a life-supporting planet. It is a region that keeps the planet warm enough to have a liquid ocean, but not so warm that the ocean boils off into space. Obviously, Earth orbits the Sun in our solar system’s “Goldilocks Zone.”

But there are other conditions besides temperature that make our part of the solar system comfortable for life. Using infrared data from the Spitzer Space Telescope, along with theoretical models and archival observations, Rebecca Martin, a NASA Sagan Fellow from the University of Colorado in Boulder, and astronomer Mario Livio of the Space Telescope Science Institute in Baltimore, Maryland, have published a new study suggesting that our solar system and our place in it is special in at least one other way.

This fortunate “just right” condition involves Jupiter and its effect on the asteroid belt.
Many other solar systems discovered in the past decade have giant gas planets in very tight orbits around their stars. Only 19 out of 520 solar systems studied have Jupiter-like planets in orbits beyond what is known as the “snow line”—the distance from the star at which it is cool enough for water (and ammonia and methane) to condense into ice. Scientists believe our Jupiter formed a bit farther away from the Sun than it is now. Although the giant planet has moved a little closer to the Sun, it is still beyond the snow line.

So why do we care where Jupiter hangs out? Well, the gravity of Jupiter, with its mass of 318 Earths, has a profound effect on everything in its region, including the asteroid belt. The asteroid belt is a region between Mars and Jupiter where millions of mostly rocky objects (some water-bearing) orbit. They range in size from dwarf planet Ceres at more than 600 miles in diameter to grains of dust. In the early solar system, asteroids (along with comets) could have been partly responsible for delivering water to fill the ocean of a young Earth. They could have also brought organic molecules to Earth, from which life eventually evolved.

Jupiter’s gravity keeps the asteroids pretty much in their place in the asteroid belt, and doesn’t let them accrete to form another planet. If Jupiter had moved inward through the asteroid belt toward the Sun, it would have scattered the asteroids in all directions before Earth had time to form. And no asteroid belt means no impacts on Earth, no water delivery, and maybe no life-starting molecules either. Asteroids may have also delivered such useful metals as gold, platinum, and iron to Earth’s crust.

But, if Jupiter had not migrated inward at all since it formed father away from the Sun, the asteroid belt would be totally undisturbed and would be a lot more dense with asteroids than it is now. In that case, Earth would have been blasted with a lot more asteroid impacts, and life may have never had a chance to take root.

The infrared data from the Spitzer Space Telescope contributes in unexpected ways in revealing and supporting new ideas and theories about our universe. Read more about this study and other Spitzer contributions at spitzer.caltech.edu. Kids can learn about infrared light and enjoy solving Spitzer image puzzles at spaceplace.nasa.gov/spitzer-slyder.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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Caption: Our solar system is represented by the middle scenario, where the gas giant planet has migrated inward, but still remains beyond the asteroid belt.

About NASA Space Place

The goal of the NASA Space Place is “to inform, inspire, and involve children in the excitement of science, technology, and space exploration.” More information is available at their website: http://spaceplace.nasa.gov/

CNYO Observing Log: Baltimore Woods, 9 February 2013

Ryan Goodson, Larry Slosberg, and I joined Bob Piekiel for his monthly New Moon observing session at Baltimore Woods on his weather-alternate session (having lost Friday’s session to Snow Storm Nemo). What started as a remarkably cold session, which then progressed to a bitterly cold session, and then finally to an intolerably cold session (forcing us to close shop up around 8:30 p.m.), still provided some excellent views of the Winter Sky, including the Solar System‘s largest planet Jupiter right between the Hyades and Pleiades.

For those who haven’t ventured for a session, the view from the Baltimore Woods parking lot includes a clear zenith (what luck!), a tree to the North that extends almost up to Polaris (so one must walk around it to get the view of constellations below our North Star), low-lying trees to the West, then the warm orange glow (the only thing warm on the 9th) of Baldwinsville and Syracuse to the East-Southeast. As we’re mid-winter, the evening observing was obstructed occasionally by blindingly bright snowmobiles (but one had plenty of lead time to take cover).

The evening started early with a fly-by of the yellow-orange ball that is (from the ground, anyway) the International Space Station (ISS), right on schedule with the predictions from heavens-above.com:

Date Brightness Start Highest point End Pass type
[Mag] Time Alt. Az. Time Alt. Az. Time Alt. Az.
09 Feb -3.3 18:55:57 10° SW 18:59:16 68° SE 18:59:56 51° E Visible

Reaching a total session count of eight, the evening included several observations of Jupiter, noting specifically how quickly Io rushed from Jupiter as even 10 minute intervals progressed (the slow cooling of mirrors resulted in many returns of increasingly crisp views). A comparison of eye piece magnifications and field-of-views was performed with the Pleiades in Bob’s 11″ Schmidt–Cassegrain and Ryan’s 16″ NMT Dob. In both cases, one my my favorite doubles, Tyc1800-1961-1 (blue) and Tyc1800-1974-1 (orange), jumped right out from the center of the tea cup. The lesson learned from such an exercise is that magnification is not the key to observational astronomy – it is seeing all that you want to see in the field of view that is key to enjoying the Night Sky.

A second highlight of the evening included M35, an open cluster in Gemini that, at 2,800 light years away, still covers an area the size of the Full Moon. Clearly visible as a slight “smudge” in the upper-left corner of the eyepiece (so the lower-right corner of M35) at low magnification is the compact open cluster NGC 2158.

After Jupiter, the night belonged to the massive Orion Nebula (M42), a hydrogen cloud doubling as a stellar nursery. At a magnitude of +4.0, the fuzzy patch in Orion’s Belt is visible to the Naked Eye, increasing in density with small binoculars, and leading to magnificent views of filamentous nebulosity at low magnification in both telescopes. The splitting of the main binaries in Trapezium was trivial in Ryan’s 16″ NMT Dob even without a completely cooled mirror.

I noted to Ryan that, given the usual CNY winter conditions, “It’s a rarity to see Pegasus in the West.” The quintet of Sirius, Orion’s Belt, the Hyades, Jupiter, and the Pleiades was worth the visit with or without equipment. After 90 minutes of observing in cold, continually patchy skies, the temperature dropped precipitously, instigating a rapid retreat and scope packing by all attendees. The lessons learned – your gloves are never thick enough & always have a headlamp in the car for the end of the evening!

Asteroid 2012 DA14 (& Little Hope For CNY (Viewing))

Greetings fellow astrophiles!

I begin with a little bit of history from the NASA Voyager website: voyager.jpl.nasa.gov

The Voyager delivery accuracy at Neptune of 100 km (62 mi), divided by the trip distance or arc length traveled of 7,128,603,456 km (4,429,508,700 mi), is equivalent to the feat of sinking a 3630 km (2260 mi) golf putt, assuming that the golfer can make a few illegal fine adjustments while the ball is rolling across this incredibly long green.

I include this piece of historical content to put into context any discussion about a 2012 DA14 impact (which, at this point, falls clearly into the conspiracy theory regime). The world has a very good handle on Newtonian Mechanics and, when it is reported by NASA physicists that something is going to miss the planet by 27,000 km (OK, fine. 27,000 km from the Earth’s center. As the point on the Earth’s surface farthest from the Earth’s center is 6,384 km away, DA14 will miss by “only” 20,616 km), you can believe it. If we can be off by 100 km after 12 YEARS in space, be assured we can be within that same 100 km with a year’s worth of data collection.

With the good news out of the way…

As the newest reports about 2012 DA14’s path make clear, its passing within geosynchronous orbit will be a treat for observers in Indonesia and an otherwise great view for Europe, Asia, and Africa. And by great, I mean that the predicted apparent magnitude will not reach smaller than 7.4 (smaller = brighter. Naked Eye viewing trails off rapidly after magnitude 4, making 2012 DA14 a “big binocular” object even at its closest approach. The Sun, on the other hand, is at magnitude –26.74 from Earth), so it will be great with the aid of optics. CNY, and the Americas in general, will only be able to observe 2012 DA14 on its “way out,” after closest approach. As it will be moving at quite a clip away from us, it will be quite a difficult object in CNY to find for anyone outside on the night of the 15th. Reports seems to indicate it will be at magnitude 11 by the time the East Coast could see it, which is a heroic magnitude for most any amateur telescope).

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CAPTION: Path of 2012 DA14 (in Universal Time (UT) and as viewed from the Earth’s Center) on February 15/16. Click for a full-sized version. From www.virtualtelescope.eu.

And, if you’re still freaked out about impact, note that we (CNY) will STILL be on the wrong piece of Terran real estate. That said, its trajectory is even wrong for colliding with geosynchronous satellites, so your cell phone service won’t be impacted, either.

I am pleased to report that the best 4 minute discussion of 2012 DA14 has been put together by an organization I’ve been a member of for over 15 years – The Planetary Society (co-founded by Carl Sagan, currently CEO’ed over by Bill Nye, the list of activities in space science and public outreach is considerable). Bruce Bett’s youtube video is provided below. If Snow Storm Nemo has anything to say about it, you’ll have plenty of time this weekend to watch and take notes.

CAPTION: Planetary Society Director of Projects Bruce Betts reassures us in this brief and fascinating explanation of what will happen–and what WON’T happen–when this big asteroid comes closer to Earth than many satellites.

You can read a full article about 2012 DA14 at the Planetary Society website: www.planetary.org/explore/projects/neo-grants/2012da14.html. A thorough FAQ can be found at www.planetary.org/explore/projects/neo-grants/2012-da14-faq.html.