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 - 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!

Question Your World - What's NASA ever done for me?

20111130 NASAinventions by ScienceMuseumofVA

Other than blasting people into space and taking photos of far off distant worlds, NASA has contributed a lot to our day-to-day lives also. Check out this page for more info on what NASA's done to help you sleep, clean, and live a little easier. NASA Inventions!

Thank you NASA!

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?

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!