Picture Of The Day Dec - 29
Picture Of The Day
2012, December, 29
(Visible-Light Image of Jupiter -- Hubble Space Telescope)
The Men On The Moon
The Men On The Moon
The human exploration of the moon lasted just over three years and involved a total of six missions. In each, a pair of US astronauts went down to the surface in a Lunar Excursion Module while a third object in a Command Service Module. The missions provided scientists with huge amout of information about the moon. The Apollo 17 duo spent the longest on the moon. They remind on the surface for 75 hours, part of that time in a lunar roving vehicle.
Twelve men landed on moon between 1969 and 1972, spanding almost 80 hours on its surface. They explored 90km of it on foot or by "moon-buggy", collected rocks, set up experiments, and played golf before returning to Earth.
In July 1969, American astronaut Neil Armstrong was at the centre of one of the most important events in human history. He was the first person to walk on the moon and became instantly famous . He spent 2 hrs 35 mins on its surface.
Apollo 11 : (July 21, 1969)
Neil Armstrong, Buzz Aldrin ( walked on moon)
Mike Collins ( command module pilot)
2 hrs 32 mins ( Total EVA)
Apollo 12 : (November 19–20, 1969)
Pete Conrad, Alan Bean ( walked on moon)
Dick Gordon ( command module pilot)
7 hours, 50 minutes ( Total EVA)
Apollo 14 : (February 5–6, 1971)
Alan Shephard, Edgar Mitchell ( walked on moon)
Stu Roosa ( command module pilot)
9 hours, 25 minutes ( Total EVA)
Apollo 15 : (July 31 – August 2, 1971)
David Scott, Jim Irwin ( walked on moon)
Al Worden ( command module pilot)
18 hours, 30 minutes ( Total EVA)
Apollo 16 : (April 21–23, 1972)
Ken Mattingly ( command module pilot)
20 hours, 14 minutes ( Total EVA)
Apollo 17 : (December 11–14, 1972)
Ron Evans ( command module pilot)
22 hours, 04 minutes ( Total EVA)
* Apollo 13, 11-17 April, was aborted and return to Earth after an oxygen tank exploded
Picture Of the Day , Dec - 28
Picture Of The Day
2012, December, 28
Messier Objects
Messier Objects
The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. Messier was a comet hunter, and was frustrated by objects which resembled but were not comets, so he compiled a list of them, in collaboration with his assistant Pierre Méchain, to avoid wasting time on them.
The Messier Catalog
became well known for a much higher purpose, as a collection of the most
beautiful objects in the sky including
nebulae, star clusters,
and galaxies.
It was one of the first major milestones in the
history of the discovery of Deep Sky objects,
as it was the first more comprehensive and more reliable list:
Only four or five objects were initially missing
because of data reduction errors, which could be figured out later though.
Today's versions of the catalog usually include also
later additions of objects observed by
Charles Messier and his collegial
friend, Pierre Méchain,
but not included in his original list.
The study of these objects by astronomers has led, and continues to lead,
to important, incredible discoveries such as the life cycles of stars,
the reality of galaxies as separate 'island universes,' and the possible
age of the universe.
List of Some Messier Objects
M1 The Crab Nebula :
M2 :
M3 :
Description: globular cluster
M4 :
Description: globular cluster
M5 :
Description: globular cluster
M6 The Butterfly Cluster :
Description: open cluster
M7 Ptolemy's Cluster :
Description: open cluster
M8 The Lagoon Nebula :
Description: diffuse nebula
M9 :
Description: globular cluster
M10 :
Description: globular cluster
Halley's Comet
Comet Halley
Orbital period : 75 years
Discovered : 1705
Last perihelion : February 9, 1986
Orbits : Sun
Discoverer : Edmond Halley
Meteor shower spawned: Orionids, Eta Aquarids
British astronomer Edmond Halley(1656-1742) was the first to prove that comets travel in orbits, making it possible to calculate when they will next be seen from Earth. He predicted that the comet he saw in1682 would return in1759. It did and was named in his honour.
- Halley's Comet is classed as a short period comet, a classification given to any comet that takes less than 200 years to orbit the Sun. It is believed that it was once a long period comet, but at some point the gravity of one of the Gas Giants (Jupiter, Saturn, Uranus or Neptune) attracted the comet. It didn't collide with any of these planets, but instead was flung into the inner Solar System towards the Sun. After orbiting the Sun, it is flung back outwards before being drawn back. This is kind of like a sling shot effect.
- Halley's Comet is darker than coal, and reflects only 4% of the sunlight it receives. It only shines brightly when it is close enough to the Sun for its dust and vapours to be burnt off.
- Halley's Comet is shaped like a peanut and is about 15 kilometres (9 miles) long, and 8 kilometres (5 miles) wide and thick.
- Halley's Comet is estimated to be 4.5 billion years old.
- Halley's Comet made of composition is comprised of water, hydrocarbons, iron, carbon monoxide, methane, ammonia, and sodium.
- The first up-close observation of the comet took place on March 4, 1986 when the Soviet Vega 1 probe started sending back images of Halley.
- Records of humans observing Halley’s Comet go back thousands of years, with appearances noted by Babylonian, Chinese and European star gazers.
- It last appeared in the inner Solar System in 1986 and will return again sometime in 2061.
-
American
writer Mark Twain was born on November 30th 1835, two weeks after an appearance
of Halley's Comet's. In his biography, he stated that he was born with Halley's
Comet, and is likely to die with it. Mark Twain died on April 21st 1910 - the
day after Halley's Comet reappeared.
(photograph of Halley's Comet was taken January 13,1986, by James W. Young, resident astronomer of JPL's Table Mountain Observatory
Date closest to Sun and Observations
25 May 240 BC : Seen in China.
10 October 12 BC : Belived to mark the deth of Roman general Agrippa.
28 June AD 451 : Belived to mark the defeat of Attila the Hun.
20 March 1066 : William believed the comet was the sign of imminent victory over king Harold at the battle of Hastings.
9 June 1456 : The defeat of the Turkish army by papal forces was thought to be linked to the comet.
15 September 1682 : Observed by Edmond Halley, who predicted its return.
13 March 1759 : The comet's first return, as predicted by Halley, proving his calculations correct.
16 November 1835 : American writer Mark Twain was born on November 30th 1835, two weeks after
an appearance of Halley's Comet's. In his biography, he stated that he was
born with Halley's Comet, and is likely to die with it. Mark Twain died on
April 21st 1910 - the day after Halley's Comet reappeared.
10 April 1910 : There was a panic as many believed the world would come to an end.
9 February 1986 : The Soviet Union
sent Vega 1 and Vega 2 to visit Halley's Comet, and the European Space
Agency sent Giotto. They recorded data and sent back images of the comet.
28 July
2061 :
Next due to appear.
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