Tag Archives: space

Mercury – NASA’s Fifth Planetary Conquest

Image of Mercury from previous Messenger missions. From NASA.

After years of planning and development, NASA’s space probe Messenger finally fell into Mercury’s orbit Thursday evening. At 9:10 p.m. of March 17, when the last rocket that projected Messenger shut off and the probe fell into Mercury’s gravity pull, scientists at the control room in John Hopkin’s University started in a round of applause.

Mercury is the fifth planet that NASA spacecrafts have orbited. Mercury is the closest planet to the sun and lacks an atmosphere. This means that Mercury’s surface is super heated by the sun during daytime but drops to hundreds of degrees below freezing at night. Also, without an atmosphere, Mercury’s surface is heavily cratered. The vast temperature different implies that ice could be found inside the craters. The Mercury probe hopes to bring back a year of photography that would help in the research of the creation of Mercury and its composition. With this goal in mind, surveillance of the probe is needed for the next few days. Constant checks on the probe’s health systems, testing of the scientific equipment that is on board is essentially so that the vast amount of data can be collected and  transmitted back to Earth.

This massive project started in 2004 with a budget of $446 million. Hopefully, the probe will bring back valuable data that would useful for planetary scientists to determine the evolution of Mercury.

Messenger also hits close to UBC as one of the Earth and Ocean Science professors, Dr. Catherine Johnson, participated in the project. Dr. Johnson is a participating scientist in the project and hopes to discover the reasons behind Mercury’s magnetic field. The probe Messenger hopefully will gather data that will be of use to Dr. Johnson.

To boldly go ever after? The search for habitable planets.

Have you ever dreamed of exploring outer space? Of reaching up into the stars to venture where no person has gone before, exploring strange and exotic worlds all the while saving mankind from imminent destruction? From Star Wars to Battlestar Galactica the imaginative world of science fiction has painted a picture of the galaxy quite dissimilar from our own. Theirs is a universe filled with habitable-world’s innumerable star systems surrounded by small rocky planets. While this makes for compelling story-lines, until recently it was thought that this view couldn’t be farther from the truth.

Earlier this month it was released that NASA’s Kepler Mission, named in honour of German astronomer Johannes Kepler whose work laid the foundations for the laws of planetary motion, had discovered its first so-called Goldilock’s planets. A Goldilock’s planet is a terrestrial (rocky) planet of a similar size to Earth in an area known as the Circumstellar Habitable Zone. A system’s CHZ is a spherical region of space surrounding a star where a planet could theoretically possess the life’s essential element, water. In this zone, planets receive enough solar radiation to keep the bulk of the water above freeing, but not so much as to boil. In addition to being in the CHZ a Goldilock’s planet must also be within a region known as the Galactic Habitable Zone (GHZ). Along the same lines as the CHZ the GHZ is a region of the galaxy where it is thought that there is the highest possibility of finding habitable planets. It is far enough away from the galactic core as to not be severely affected by the high-energy radiation common there, but not too far as to be devoid of the heavier elements essential for the formation of terrestrial planets. In the Milky Way this regions starts at around 25,000 lights years from the galactic core and extends to about 32, 000 ly.

While the candidate planets discovered by the Kepler Mission will require careful follow-up to determine if they are indeed Earth-like planets, preliminary observations suggest that five of the fifty-four planet candidates in the CHZ are indeed terrestrial, and similar in size to our own. A new device from the Harvard-Smithsonian Centre for Astrophysics will likely play a key-role in verifying the characteristics of these new worlds. Knows as the High-Accuracy Radial velocity Planet Searcher or HARPS-North for short, the instrument soon to be installed in the Canary Islands will enable researchers to measure the tiny radial-velocity signal produced by small planets like the Earth. This data allows researchers to determine the densities of the target-planets enabling them to distinguish terrestrial worlds from their more common gas-based brethren.

While these five planets represent a tiny fraction of the over 1200 planet-candidates found thus far during the analysis of over 150,000 star systems discovered by the Kepler Mission, that they were all located in such a minuscule fraction of the galaxy suggests that a universe of boundless habitable-worlds might not be too outside the realm of possibilities.

References Cited:

  1. NASA (2011, February 2). NASA finds Earth-size planet candidates in habitable zone, six planet systemScienceDaily. Retrieved February 16, 2011, from http://www.sciencedaily.com­/releases/2011/02/110202133321.htm
  2. ANI. (2011, 2011-02-15). New device to help confirm kepler’s planetary candidates. The Wall Street Journal,
  3. Mori. (2007). Fermi , what paradox? (image credit). Retrieved 02/15, 2011, from http://forgetomori.com/2007/ufos/fermi-what-paradox/

The New Heavyweight Champion of the Universe

EDIT: added in another image of star cluster R136

Ladies and gentlemen, let me introduce you, to Hypergiant “blue” R136a1, “The New” Solar Mass Heavyweight Champ! Weighing in at an estimated 265 solar masses, he may very well be the most massive star in our universe! He’s  so big, that scientists are baffled by how he came to be.

Size Comparison for R136a1

You heard it folks, there’s a newly discovered star, that’s so heavy that it disputes current models of how stars may be formed. R136a1 was discovered last year with the findings published in July 2010. It’s found in a star cluster known as R136 that’s 165,000 light-years away.

In 2005 NASA had released an article which suggested that in our current era of the universe, stars cannot exceed 150 solar masses (i.e. 150 times the mass of the sun) otherwise they would violate the Eddington Limit. This limit is where the radiation force outwards of a star is equal to the gradational force pulling inwards. Stars bigger than this would have too much out flowing radiation that they would eject all their gaseous matter into space.

This may be the case for R136a1: scientists speculate it was actually much heavier at its formation and may have lost as much as 50 solar masses through continuous emission of stellar winds in the last million years due to its instability. So, how did R136a1 come to be? Scientists speculate that its ridiculous size may be attributed to several young stars colliding together to form a single object.

Size Comparison for VY Canis Majoris

One thing to keep in mind is that while R136a1 is the heaviest known star, at only 35 solar radii (i.e. 35 times the radius of the sun), it is certainly not the largest. The title of “biggest star” belongs to VY Canis Majoris that is 1800-2,100 solar radii in size! At the same time, it is only 30 times the mass of our sun.

As for its fate, R136a1 is too big to form a black hole and may instead explode as hypernova (an explosion equivalent to over  100 supernovae). Of course, that’s only if it doesn’t blow all of its matter into space before then..

The original article can be found here (#83, “The Biggest Star of All”):  http://discover.coverleaf.com/discovermagazine/201101?pg=76#pg76

NASA’s 2005 article can be found here:  http://www.nasa.gov/home/hqnews/2005/mar/HQ_05071_HST_galaxy.html

For more general information on hypergiant stars, see:  http://en.wikipedia.org/wiki/Hypergiant

Hubble - R136 - Stellar Nursery