Question Your World: Can we live on another planet?

Somewhere around 4.5 billion years ago a gigantic ball of mass started to take shape and would eventually become where we all live.  So, the notion of a planet that can harbor life is not a strange one - after all, we happen to live on one.  Are there any other places that are similar? Can we live on another planet?

For the past 200,000 years or so humanity has been here on Earth.  In that time we've figured out how to use fire, harvest crops, change water streams, develop communities, embrace technology and learn about what happens beyond our tiny little cosmic stage.  Not bad for a new species!  Regardless, one thing we have yet to do is gain tactile proof of life existing anywhere else in the universe.

In order to search for life in other parts of the universe one needs to have a basic set of requirements. For example, the functionality of everything we know here on Earth can be traced back to our sun, so to look for other similar situations we must look at other stars (suns).  Well, we also know that the Earth is both rocky and has water.  Those are two more qualifications needed to search for similar conditions.  There's also the matter of temperature.  For example, Mercury is very hot, too hot to hold any life as we know it.  Similarly the moons of Pluto are far too cold for our taste.  Thus the position of the planet relative to its host star is a big deal as well.

Also, keep in mind, looking for planets is no easy task, the stars they orbit are so far away that we only see them as little dots of light in the night sky.  Scientists have tried various methods such as the wobble or transit methods to hone in on and fine tune their understanding of such faint and distant worlds. However, this incredibly complicated process has shown some remarkable data.  For example, in recent years we've gathered enough data to say that there's a really good chance that planets outnumber the stars in our universe.  NASA's official exoplanet list grows all the time and we're up to over 8.8 billion potentially trip-worthy planets in our Milky Way galaxy alone.  Regardless, it takes a lot of factors in just the right balance to allow for comparable conditions to our home here on Earth.

Our Earth is a good size, one that can use its gravitational pull to keep our atmosphere.  Aside from that, our distance from the sun allows for tolerable temperatures and the existence of liquid water.  Those two are very important aspects of planet-hunting.  As of now we're the only place in the known universe to be this size and this distance from our host star.  Well, we were the only place...

Recently, scientists used data from the Kepler Space Telescope and announced the first ever exoplanet discovered to be a similar size and a safe relative distance from their host star.  Kepler 186f is one of 5 planets that orbits its red dwarf star.  How far is it? About 500 light years from here - bring a book, it's a long trip.

So, we may not be able to go visit this place anytime soon, but this discovery is very important as it highlights the possibility of another life-harboring situation out there.  It has taken us around 200,000 years to get from the first time we opened our eyes to today where we can learn about the vast distant reaches of the cosmos.  The work that lays ahead for future generations could yield some remarkable findings on our universe, its creation and perhaps even a better understanding of who or what we are in the grand scheme of things.

Kepler 186f now joins the billions of other exoplanets discovered, but stands out with the distinction that it's the first exoplanet that meets a lot of the special qualifications needed to hold the most mysterious part of our universe, life.

QUESTION YOUR WORLD - How long is a light year?

So, how long is a light year...short answer: Long!!! long answer: about 5.9 trillion miles!!! That's how quickly light can traverse across space. So if you wanted to walk the distance of a light year you would need to be marching on your feet for about 168 million years!! For you to arrive at this moment, you would have had to start walking from the time when dinosaurs ruled the earth! Whew...better pack a few lunches for the calories you would have been using up! The speed at which light travels is still the fastest known speed in our universe.

On a related note, there sure are a lot of movies that make reference to this amazingly fast speed. Warp speed, Hyperspace, and Ludicrous speed are all references to the fastest known speed that we humans have been able to identify!

Check out more info on light year and big stellar distances here: Distance!


Also, Cool Cosmos has some pretty cool info about some of these huge distances and times!

Question Your World - Stellar Headlines!

A lot of space related news has happened in the last month. Here are some of the highlights of what's happening out there...way out there.

Huge news from NASA. The MSL (Mars Science Laboratory) launched in late November and is expected to arrive on the Martian surface in August of 2012. This one ton robot will rove the planet looking for soil samples that show if Mars was or was not ever capable of holding life. This will be a huge step forward in researching the types of conditions in the universe that could or could not hold life! For more info on the MSL please go to http://mars.jpl.nasa.gov/msl/



In other news, the Voyager 1 satellite has left the solar system!!! That's right, this officially is the very first human made object to leave the solar system. This probe is about 10 BILLION miles away from Earth right now and is, amazingly, still communicating with us. Voyager 1 was launched in 1977...pretty far out!

Lastly, big big big news from 600 light years away. Kepler 22b has been confirmed as an "Earth-like" planet. This newly discovered planet is 600 light years away, about 2.5 times larger than Earth, and orbits a star very similar to our own sun. Scientists think that the average temprature on Kepler 22b is about 70 degrees, how lovely. More on this discovery can be found right here, http://en.wikipedia.org/wiki/Kepler-22b





Happy Holidays and we'll catch up with more Stellar Headlines next month!

Neptune

A lot has been discovered about Neptune since its initial sighting in 1846. The Voyager 2 spacecraft, on Aug 25, 1989, did a fly by of this blue celestial giant and sent back some photos and other data that has helped the science community understand more about the last planet on the block. Here are some interesting factoids about Neptune:
8th Planet from the sun
Gaseous Giant
13 Moons
Named after the Roman god of the oceans, Neptune
Has rings…just like all the other gaseous giants
2.68 BILLION miles from Earth at its closest point in orbit
60,190 Earth days (164.8 Earth years) for Neptune to orbit the sun once!!
Looks cool…because it is VERY cool…as in cold -330F (72 Kelvin)…(-201 C for the non-US friends of the Science Museum of Virginia)…brrr!
After 2006's demotion of Pluto, this blue gaseous giant became the last official planet in our solar system.

Scheila Sports a Plume

Meet Scheila and her friends:

http://www.nasa.gov/topics/universe/features/asteroid-collision.html

An asteroid named Scheila lives in the asteroid belt between Mars and Jupiter with millions of other asteroids.  Scheila is about 70 miles across and completes her orbit around the sun every five years.  Late last year, astronomers noticed Scheila had gotten noticeably brighter and was adorned with plumes.  After studying data from the Hubble Space Telescope and Swift satellite, they determined Scheila had collided with one of her fellow asteroids at 11,000 miles per hour (ouch!).  The plumes made Scheila appear comet-like and were most likely small particles of dust from Scheila’s surface.  In two months, the dust had dissipated and Scheila was back to normal.  Thanks to Hubble and Swift, astronomers could study the collision before all evidence of it disappeared, allowing them a peek inside an asteroid.  Now I wonder what Scheila thought of that…

Question of the Week

Space, the final frontier...

Today at 4:50 pm, space shuttle Discovery will blast off on its final mission into space.  On board Discovery are six astronauts, the Permanent Multipurpose Module which will become sort of a storage closet for the space station, and Robonaut 2, the first dextrous humanoid robot to go into space. Robonaut 2 will test his ability to operate in zero gravity and will eventually become an astronaut's helper.


If astronauts received frequent flyer miles while in space, how many would they receive on a typical shuttle mission?

Answer:  The typical shuttle mission orbits the Earth 250 times - about 6.6 million frequent flyer miles!

Is It Winter Yet? Maybe, Maybe Not…

Snow frozen onto a tree in Germany.
Photo courtesy of Wikipedia

Tuesday, December 21, is the Winter Solstice and usually considered the first day of winter. However, meteorological winter is already here! So what’s the deal? Well, the definition of winter depends on whom you ask.

A meteorologist defines winter as the three coldest months of the year: December, January and February. An astronomer defines winter as the three months between the Winter Solstice (December 21 or 22) and the Spring or Vernal Equinox (March 20 or 21). What’s the difference?

The definition of meteorological winter is fairly straightforward. Climatologically-speaking, the three coldest months of the year are December, January and February in the Northern Hemisphere. Therefore, meteorological winter begins on December 1 and ends on February 28 (or 29). In the Southern Hemisphere, the seasons are reversed, meaning if you lived in Rio or Buenos Aires, summer would begin in December and winter would begin in June.

Astronomical winter begins on the Winter Solstice, the shortest day of the year. The Earth has seasons and variable daylight hours because its axis is tilted 23.5° relative to its orbit around the sun. Winter in the Northern Hemisphere occurs when the northern half of the planet is tilted away from the sun. This tilt causes sun’s energy to be weaker on the Earth’s surface because:

• The sun shines on the Earth’s surface at an oblique angle.
• The sun’s energy is spread out over a larger area, diluting its strength. 
• The sun’s rays travel through more atmosphere before they reach the surface. 
• Days are shorter so there is less time for the sun to heat the surface. 

Less energy from the sun on the Earth’s surface means colder temperatures in the atmosphere – so winter arrives. For more information, check out last year’s blog about the Winter Solstice: http://sciencemuseumofvirginia.blogspot.com/2009/12/winter-solstice.html

Here are some questions for you to ponder:

• If the Earth’s axis had no tilt, would we have seasons? 
• If the tilt was at a greater angle, what would our seasons be like? 
• Do you think other planets in the solar system have seasons too? 
• How did Earth’s axis get tilted in the first place?

Watch the Sky Show: the Leonids

Want to wish upon a falling star? This is the week - the Leonid Meteor Shower peaks tomorrow. Earth is currently passing through the “tail” of Comet Tempel-Tuttle. Often called a “dirty snowball,” a comet usually orbits the sun in an elliptical orbit. The comet’s nucleus, consisting mostly of ice and dust, heats as it approaches the sun. Particles begin to stream out behind it and form the comet’s “tail.” As Earth passes through this “tail” the particles collide with the atmosphere and we see a meteor shower.


Best viewing of the Leonids will be just before dawn on Wednesday, November 17 in the eastern sky (see above map). Scientists estimate this year’s show will produce 15 to 20 meteors per hour (a sighting about every 4 or 5 minutes). Meteor showers are notoriously difficult to predict - there may be many more or there may be less.

The waxing gibbous moon will set in Richmond about 4 hours before sunrise tomorrow, so the bright light of the moon will not inhibit viewing in the early morning hours. However, clouds and showers may accompany a cold frontal passage in the Richmond area early Wednesday morning. Let’s hope we get lucky and the skies clear before dawn. But there is another chance - the Leonids may be visible just before dawn on Thursday morning also.

A few tips for best viewing:

 • Find an open area away from city lights with no tall buildings or trees in the eastern sky.
 • Take some friends – it’s always more fun with someone along.
 • Let your eyes relax and look all around - binoculars not required. Actually, your eyes will find the meteors  better without binoculars because they have a broader range of vision.
 • Take some equipment for maximum enjoyment:
        o Lawn chair – be comfortable; kick back and relax.
        o Blankets or sleeping bag – bundle up; it will be chilly (50’s).
        o Hot coffee or tea in a thermos.
 • Binoculars might be useful for observing fireballs, unusually bright meteors that leave an incandescent streak lasting as long as a few minutes. Winds in the upper atmosphere will bend and distort the streak; binoculars will give you a close-up view.

Interesting fact (from http://www.space.com/ ): When a comet takes 33 years to go around the Sun, it goes way out there and tends to get lost. Comet Tempel-Tuttle gets lost a lot. It also gets found now and then. Tempel-Tuttle was "discovered" by William Tempel in late 1865 and independently by Horace Tuttle in early 1866. Nobody saw Tempel-Tuttle again for almost 100 years (1965). Then on March 4, 1997, armed with great orbital data, Karen Meech, Olivier Hainaut and James Bauer at the University of Hawaii "recovered" the comet yet again. Tempel-Tuttle will next return to the inner solar system in 2031.

For more information, go to http://www.space.com/.  Star map credit: Stardate.

Thoughts on Virginia’s Goodwill Moon Rock

Thirty-eight years ago I stood with my younger brother on a shoreline near midnight looking eastward across 12 miles of quiet, dark water at the brilliant jewel on the far horizon. A million people lined the beaches as far as we could see. In the distance xenon arc lights crossed upon the largest craft ever to carry humans. The thunderstorm that had earlier sent tendrils of blue and orange lightning beyond the gantry had since moved far out to sea.

At the final countdown the night burst into a blaze of silent light and the sky glowed crimson to the far horizon behind us. A full minute would pass before the sound hit us, a deep shattering moan shaking our rib cages, the trees and cars. The last Apollo Saturn V rocket lifted with the inexorably slow climb of a freight elevator. Our 8mm film would show its three stages burning successively into orbit in the clear, beautiful night.


In that minute before the rocket's sound reached us, the collective expression of the human spirit, in all its aspirations, went up from the multitude on the beaches. The shouting, weeping, praying and cheering of a million voices blended into a roar that lifted with the three on their way to the moon.

Human space flight inspires in ways that more cost-effective robot probes do not. This experience fueled my drive to study physics.

These are my thoughts this summer as I had the challenge of gathering and arranging information and images about the Apollo missions to the moon. The result of this curatorial work would become part of the exciting, new installation and display of the museum’s Apollo 17 moon rock -- in a new setting that directs the visitor’s attention to one of the rarest objects on Earth.

As I worked in the Stardome room (at the north end of the Main Concourse) with the moon rock case nearby, I thought about the coincidence that I had witnessed the launch of that very mission in December of 1972.

From that mission Harrison Schmitt brought back 242 pounds of lunar material, including the Goodwill Rock that provided the plaque-mounted specimens given to every U.S. state and territory and every nation on earth in 1973.


Apollo science is still alive in some ways today. Three Apollo missions left retro-reflector arrays on the moon to bounce laser light back to Earth. These arrays allow scientists to measure daily the distance and the motion of the moon away from Earth, at about an inch and a half a year.


Another final milestone approaches. The last and final Space Shuttle flight (the 134th ) has been authorized for launch next summer. Next August the NASA will leave manned space flight to others, possibly for decades. The Space Shuttle is the most complex thing ever built, with 2 ½ million parts and 230 miles of wiring. These difficult economic times make it hard to justify the extravagance of human space exploration.


We have, however, a rich and long history of unmanned space probes. Our 1970s launches of Pioneer 10 and 11, and Voyager 1 and 2 yielded a treasure trove of dazzling images of the outer solar system and are now far beyond it. They carry gold plaques and phonograph records explaining the culture of the species from Earth that sent them.


And we continue to roll out ever more sophisticated unmanned spacecraft. A long range probe is on its way to Pluto. A replacement for the Hubble Space Telescope is under construction, with 15 times Hubble’s light gathering ability. Other orbiting telescopes are looking for extraterrestrial planets. Further unmanned probes are planned for Mars and the moon. Others may explore oceans of salt water beneath the ice on Europa and Enceladus, moons of Jupiter and Saturn.


Oh, yes. We actually did go to the moon. Had we not gone, telescopes all over the Earth would not have recorded, as they did, the flights and the return journeys. Russia and the rest of the world would have called our bluff. Indeed, Russia cancelled its manned moon program largely because of the verified success of our Apollo program.


So, I return in my thoughts to the museum’s Apollo 17 moon rock, a small, three billion year-old memento of a trip made 38 years ago.

David Hagan
Museum Scientist
Science Museum of Virginia

Happy Birthday, Voyager 2!

For an incredible 33 years, Voyager 2 has been our eyes of discovery in the outer solar system and beyond. This venerable spacecraft has been in continuous operation more than 12,000 days, sending us compelling photos and information about the gas giants of the solar system: Jupiter, Saturn, Uranus and Neptune. Now headed into interstellar space beyond the solar system, the spacecraft is still transmitting invaluable data about the solar wind and deep space beyond the planets.

On August 20, 1977, Voyager 2 blasted off from Cape Canaveral, FL on a mission to the giant planets of the solar system. Its sister spacecraft, Voyager 1, was launched a few days later on September 5. Both original missions were intended to study just Jupiter and Saturn. However, both continued sending data beyond those planets, and thanks to these intrepid spacecraft, we have now had a close encounter with every planet in the solar system. (Pluto is now called a “plutoid” and is no longer considered a planet.)

(Just think, the computers on these spacecraft were made in the 1970’s and they are still working! Pretty remarkable, huh?)

Here are a few fast facts about the Voyager mission:

• Explored all giant planets of the outer solar system
• Explored their 48 moons and unique ring systems
• Closest approach to Jupiter - 1979
• Closest approach to Saturn - 1980 (Voyager 1); 1981 (Voyager 2)
• Closest approach to Uranus – 1986 (Voyager 2)
• Closest approach to Neptune – 1989 (Voyager 2)
• Carry a golden record with a greeting from Earth
• Now the most distant human-made object in space (Voyager 1)
• Distance from sun - 17 billion km (Voyager 1); 14 billion km (Voyager 2)
• Signal from Earth takes over 12 hours to reach spacecraft
• Crossed termination shock, where solar wind slows abruptly, in 2004 (Voyager 1); 2007 (Voyager 2)
• May have reached or will soon reach Heliopause or entry into interstellar space
• Currently, 5 teams investigating: Magnetic fields, Low energy charged particles, Cosmic rays, Plasma (Voyager 2), Plasma waves
• May continue to operate and send data until around 2020

Long-lived Voyager has been documented often in fiction and pop culture (remember “V’ger” in the Star Trek movie?). So Happy Birthday, Voyager! May you live long and prosper!

The International Year of Astronomy

By David Hagan, Staff Scientist, Physical Sciences

The International Year of Astronomy 2009 (IYA2009) is a celebration of the 400th anniversary of astronomy as a modern science. In 1609, while Virginia’s tiny colony at Jamestown was struggling to survive, Galileo began looking through his telescope to the heavens for the first time and opening a vast world of wonders. His discoveries and his courageous publications confirmed Copernicus’ model of a sun-centered solar system. Galileo gave us new details of Jupiter’s moons, the phases of Venus, sunspots, and craters and mountains on the moon. That same year Johannes Kepler published "Astronomia Nova," a masterful and rigorous mathematical explanation of the motion of the planets in a sun-centered solar system. Together that year Kepler and Galileo launched not only a new astronomy, but — in some ways — the beginnings of modern science.  

The International Year of Astronomy 2009's mission statement lays out a “global effort initiated by the International Astronomical Union (IAU) and UNESCO to help the citizens of the world rediscover their place in the universe through the day- and night-time sky, and thereby engage a personal sense of wonder and discovery.”

It is a sad fact that, because of the glare of city lights, most of the people in the modern world will never see the wonder of the natural night sky or the Milky Way. Project Globe, a partner in IYA2009, reports that 2 out of 5 Americans, 1 out of 6 Europeans and 1 out of 10 people worldwide have never seen 90 percent of the visible stars in the night sky. With half the world’s population now living in cities, this problem is only getting worse. It is the vision of the International Year of Astronomy 2009 that all people on earth should “realize the impact of astronomy and other fundamental sciences on our daily lives, and understand how scientific knowledge can contribute to a more equitable and peaceful society.”   

Hundreds of IYA2009 programs are under way around the world on a national, regional and local level, with coordinators each country. Throughout the year in the United States coordinating links are being set up among professional and amateur astronomers, science centers and science communicators. Worldwide, 136 countries are involved and well over 140 are expected to participate eventually. The IAU has set up an IYA2009 Web site, www.astronomy2009.org, as the principal IYA2009 resource. The International Year of Astronomy 2009 is endorsed by the United Nations, UNESCO (United Nations Educational, Scientific and Cultural Organization) and the International Council of Science (ICSU).  

One of the great projects of IYA2009 is the Galileoscope. IYA2009 has set a goal to have 100,000 people — each with a hand-held telescope — show the night sky to 100 others, so as to reach 10 million new observers. The Galileoscope is an inexpensive ($15) working hand-held telescope modeled on Galileo’s first telescope. For more information see the Web site https://www.galileoscope.org/gs/ 

In the United States the IYA2009 programs are coordinated through the Web site http://astronomy2009.us/. NASA is a key supporter of IYA2009 programs. Their Web site is http://astronomy2009.nasa.gov/news.htm