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/>.