APOD 2.4

Atoms-for-Peace Galaxy Collision

This is a picture of NGC 7252, the result of two large galaxies colliding.  The full collsion will take hundreds of millions of years.  The combined galaxies has been given the nickname "Atoms-for-Peace" because it looks similar to a giant atom.  Atoms-for-Peace spans about 600,000 light years and is about 220 million light years in the direction of the constellation Aquarius.  It is not unlikely that this will someday happen to our Milky Way!  Our galaxy could perhaps collide with the nearby Andromeda Galaxy!!

APOD 2.3

NGC 4452: An Extremely Thin Galaxy

While to most people this picture would look simply like a bright line in the sky, astronomers are able to identify it as a galaxy being seen perfectly edge on.  This galaxy, known as NGC 4452, belongs to Virgo Cluster of Galaxies.  Because it is a disk galaxy, it makes it hard to determine what type of galaxy it actually is.  It is likely a low-dust lenticular galaxy because of its lack of a visible dust lane.  NGC 4452 has an estimated span of 35,000 light years.  Our own Milky Way is thought to be just as thin as this galaxy!!

APOD 2.2

Spicules: Jets on the Sun

The Sun is covered with thousands of young spicules.  These spicules are pipes of transparent magnetic fields filled with hot gas moving 50,000 kilometers per hour.  Each pipe is as wide as a state and as long as Earth! In this particular picture, the spicules are extremely evident in the converging sunspot in the lower left corner.  Spicules usually only last about five minutes.  They start out as very tall tubes and rapidly decrease in size.  It is amazing how incredibly high resolution this picture is!  What determines the actual creation of these spicules is still unknown.

APOD 2.1

Mirach's Ghost

NGC 404, or Mirach's ghost, is a very faint galaxy that is seen along the line of sight of the bright star, Mirach.  Mirach is also known as Beta Andromedae.  It is a giant red star located about 200 light years away.  While it is cooler than the sun, it is still much larger and much brighter! The galaxy is called Mirach's ghost because when looking at it through most telescopic views, it appears to be a ghostly internal reflection of the overwhelmingly bright star.  There is a lot of glare and diffraction which makes Mirach's Ghost hard to see. It is amazing that we are even able to see this galaxy at all since it is located over 10 million light years away!!

APOD 1.8

To some, this large bright feature coming over the edge of the Sun, may look like some kind of monster, but it is in fact a solar prominence.  Solar prominences are bright features anchored to the sun which extend outward into the Sun's corona.  This particular one is extraoridnary because it is the largest one on record!  How big? The entire Earth could fit inside!  This solar prominence is an eruptive prominence, which means it will erupt in only a few hours, turning into hot gas which will be emitted into the solar system.  Because the Sun is heading toward solar maximum, even larger eruptive prominences are possible!!

Johannes Hevelius Biography

Johannes Hevelius

Johannes Hevelius, also known as Johannes Hewelke, was born into a wealthy, protestant, German-Polish family on January 28, 1611.  He was born in Danzig, a city now part of Poland and his parents were Abraham Hewelke and Kordula Hecker.  He came from a family of very successful brewing merchants.  In 1630, Hevelius studied jurisprudence, the theory and philosophy of law, at Leiden.  He then travelled England and France.  In 1634 he returned home to Danzig, where he eventually became a town councillor.  A year later he married his neighbor, Katherine Rebeschke.

Johannes Hevelius took an interest in astronomy from a very early age, but from 1639 on, astronomy was his sole interest.  He was extremely talented and handy, building his own observatory in his house in 1641.  This observatory contained several impressive instruments, including a Keplerian telescope of 150 feet focal length (he also built this himself).  Although he had this large instrument, he is still considered the last astronomer to do major work without a telescope.  In 1660 his talents and work were recognized by the queen and king of Poland, who visited his observatory.  Hevelius became the first German member of The Royal Society of London for the Improvement of Natural Knowledge, known simply as the Royal Society, in 1664.  On September 26, 1679, his observatory, instruments and books were tragically destroyed in a fire.  He quickly repaired the damage, but the shock from the fire lead to bad health and ultimately death.  He died on January 28, 1687.  

Hevelius made several contributions to astronomy, but he is most known for being the founder of lunar topography, dedicating four years of his life, 1642 to 1645, to charting the moon’s surface.  He discovered the moon’s libration in longitude.   He made many observations of sunspots, and he discovered at least four comets.  He suggested that these comets revolved in parabolic tracks around the sun.  Hevelius also discovered and described ten new constellations, however only seven are still recognized by modern astronomers.  

Johannes Hevelius published many works throughout his lifetime, including Selenographia, Annus climactericus, Prodromus cometicus, Cometographia, Machina coelestis, and Prodromus astronomiae.  In Selenographia, his most famous work, Hevelius recorded his discoveries of lunar topography.  He described the catastrophe of the fire in Annus climactericus.  Prodromus cometicus, Cometographia, and Machina coelstis contain descriptions of his instruments and observations.  Lastly, his catalogue of 1564 stars appeared in Prodromus astronomiae.  Johannes Hevelius was clearly an extremely talented man and a very large contributor to the world of Astronomy.

APOD 1.7

Moonquakes Surprisingly Common

The Apollo moon landings left seisometers on the moon, which have recently revealed a shocking number of moonquakes!  These moonquakes are occurring within only 30 kilometers of the moon's surface.  Between 1972 and 1977, 28 moonquakes were recorded.  Not only are there several moonquakes, they are surprisingly long: longer than Earth's soft rock Earthquakes.  The stiff rock causes the moon to vibrate for several minutes, and they are strong enough to move furniture.  The only hypothesis of these moonquakes are that landslides cause the vibrations.

APOD 1.6

This is an image of Jupiter's moon, Io, that was taken in July, 1999.  The Galileo spacecraft took this picture during its orbit of Jupiter from 1995 to 2003.  It is the strangest moon in the solar system due to its bright yellow color, which is the result of sulfur and molten silicate rock.  The surface is covered with active volcanoes created by friction from Jupiter's other Galilean moons.  Some of the lava is so hot that is glows in the dark!!

http://apod.nasa.gov/apod/ap101003.html

APOD 1.5

Astronomers have recently discovered a potentially habitable planet about 20 light years away from Earth! It orbits a red dwarf star and has been given the name Gliese 581g, but is more commonly called Zarmina's World (named after the wife of the astronomer who made the discovery).  Zarmina's World has a 37 day orbit and a mass 3.1 times bigger than Earth's.  This amazing discovery indicates that there may be many other habitable planets in just the Milky Way alone!  It makes you think about the fact that Earth could very possibly be not the only planet with life.

http://apod.nasa.gov/apod/ap101001.html

Sources

Dictionary of Scientific Biography, C. Gillispie, editor. Charles Scribner's Son. 1981.

"Johannes Hevelius." NNDB: Tracking the Entire World. Web. 01 Oct. 2010. <http://www.nndb.com/people/649/000096361/>.

APOD 1.4

Dark Clouds of the Carina Nebula

The Carina Nebula can be found in the constellation of Carina, which is about 7,500 light years away, and it has a span of about 300 light years!  It contains two of the most massive stars in the Milky Way galaxy- Eta Carinae and HD 93129A. I have now looked at and admired many different pictures of nebulae, but this one particularly stands out from the rest! The Carina Nebula has many dark clouds in it.  These clouds are made up of such thick gas and dust that they actually become opaque, but yet they are still less dense than Earth's atmosphere.

September 22, 2010

Tonight was the night of the autumnal equinox! The moon is a beautiful sight in the sky.  It is completely full.  There were a few clouds in the sky, but many stars were still visible.  I was able to identify Jupiter, which looked like a bright star slightly below the moon.

I will continue to observe the night sky, looking out for the movement between Jupiter and the moon!

APOD 1.3

The Veil Nebula

A nebula is an expanding cloud that is the result of an exploding, massive star.  Light from the original supernova explosion that caused The Veil Nebula, likely reached Earth about 5,000 years ago! It is 1,500 light years away, and appears to have a span of 6 times the diameter of the moon.  That means it is approximately 70 light years wide! It is hard for the human mind to even understand such massiveness.  The veil nebula is so large that the brighter parts of it are considered to be seperate nebulae. 

APOD 1.2

NGC 4911: Spiral Diving into a Dense Cluster

What an incredible picture! I had no idea that we had the technology to take a photograph of an entire galaxy! I learned that NGC 4911 is one of the millions of spiral galaxy.  It is currently in the beginning of the process of becoming an elliptical galaxy, which means it will be nearly featureless.  NGC 4911 is being pulled at by neighboring galaxies causing faint rings around it.  This constant pulling will eventually cause the spiral galaxy to fall into the Coma Cluster of Galaxies, one of the most massive objects known.  When this happens dust, gas, and surrounding satellite galaxies from NGC 4911 will be lost, and the galaxy will turn a yellowish color.

APOD 1.1

Comanche Outcrop on Mars Indicates Hospitable Past

I had never imagined Mars to look like this, nor did I ever think I would be able to see such a vivd and incredible picture of this foreign planet.  Because there is no water on Mars, it would be physically impossible for any life on Earth to survive there.  Martian rovers have found evidence that indicates that there may have been water on Mars surface many years ago, but this water was likely too acidic for any Earth life forms.  However, an outcropping on Mars' surface, given the name "Comanche", was recently discovered.  Comanche gives evidence that Mars has not always been so acidic. The outcrop has a very high concentration of magnesium iron carbonate.  Carbonate dissolves in acid, meaning that there is the possibility that less acidic water once flowed through Mars! This means there could have been life on Mars!!!