Archive for April, 2009

Colliding Galaxies: I’ve heard that the Milky Way (our home galaxy) is in a collision course with another galaxy. Is this true and if it is, what does that mean for Earth?

Reader Questions | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

It is true that astronomers believe that the Milky Way is in a collision course with our neighbor, the Andromeda Galaxy.  The thing that might be surprising is many galaxies collide with each other.  This is not an overly unique event.  With so many galaxies zooming around the Universe in relative close proximity with each other, collisions are inevitable and fairly common.  To see some cool pictures of galaxies in collision go to the following website: http://apod.nasa.gov/apod/colliding_galaxies.html

NGC 4676: When Mice Collide

NGC 4676: When Mice Collide

When you think about galaxies colliding with each other, it is not like two cars crashing into each other.  The galactic collision takes place over millions and billions of years.  Also when galaxies collide they don’t actually strike one another, they simply pass through each other.  Few if any stars actually strike one another.  For a really nice animation of two galaxies colliding, go to this website: http://www.haydenplanetarium.org/resources/ava/galaxies/G0601andmilwy.

Some astronomers calculate that the Milky Way – Andromeda collision may take place from 2 billion to 10 billion years from now.  During the collision, the stars making up the two spiral galaxies would slowly meld into a more elliptical combo galaxy, “Milkomeda” or “Andromedy Way” (whichever you prefer).  Although most of the stars would be too spread out to collide, each of the galaxies’ gravity would jostle the others’ stars.

Some astronomers feel that after the collision, the Sun may become a member of the Andromeda Galaxy instead of the Milky Way as they spread apart again.  The estimates are tentative at best and, as one astronomer put it, fun to ponder.

For an interesting article about the Milky Way and Andromeda collision, read this website: http://www.sciam.com/article.cfm?id=when-milky-way-and-andromeda-collide-earth-could-find-itself-far-from-home.

Celestial Feature of the Week: M108

Celestial Feature of the Week | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

Charles Messier wrote in his catalog that M108 was discovered by Pierre Mechain on February 19, 1781.  This Spiral Galaxy is located in Ursa Major close to the Owl Nebula (M97).

M 108 by Hunter Wilson

M 108 by Hunter Wilson

Astronomers calculate that M108 is about 45,000 light-years from Earth and has a visual brightness of magnitude 10.0.  This makes it fairly dim.  Nonetheless, M108 is fairy easy for amateur stargazers to see through a small telescope, despite its implied difficulty by its visual magnitude.

M108 is saucer-shaped and well defined.  It does not have a central budge even though we are getting a nice side view of it.  To see some beautiful pictures of it, go to the following website: http://seds.lpl.arizona.edu/messier/more/m108_more.html

You can see this galaxy early in the evening looking north toward the Big Dipper.  It will be just above the western end of the bowl stars.

Today in History: 4/26/09 – 5/2/09

Space History | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

April 28, 1928: Eugene Merle Shoemaker was born (1928–1997).    Dr. Shoemaker spent his professional life in the quest of learning all he could about impact craters and orbit-crossing asteroids.  He received a National Medal of Science in 1992 and in 1993 co-discovered Comet Shoemaker-Levy 9 which collided with Jupiter in 1994.  One of his aspirations was to be an astronaut and go to the Moon but was thwarted by a medical condition.  After an untimely accidental death, Dr. Shoemaker’s cremated remains were carried to the Moon by the Lunar Prospector space probe.  He is considered the “Father” of the science of Near-Earth Objects.

Eugene Merle Shoemaker

Eugene Merle Shoemaker

April 28, 2001: Dennis Tito became the first “tourist” in space aboard the Soyuz TM-32.  Soyuz TM-32 is a Russian passenger craft that was launched from Baikonur by a Soyuz-U rocket. It carried a three man crew (two Russian and one American, the latter not a professional astronaut) to the International Space Station, ISS. It docked automatically with the ISS at 07:57 UT on 30 April, just a few hours after the shuttle STS 100 undocked. The crew stayed for a week.

Soyuz TM-32 Crew

Soyuz TM-32 Crew

May 1, 1949: Gerald Kuiper discovered Nereid, a moon of Neptune.  In his career Kuiper is also credited for discovering one of Uranus’s moon Miranda.  He was born on December 7, 1905 in North Holland and became a naturalized citizen of the United States.  He was blessed with extraordinarily sharp eyesight, allowing him to see magnitude 7.5 objects with his naked eye.  This is about four times fainter than someone with normal vision!

Nereid

Nereid

May 2, 1965: the “Early Bird” satellite was used to transmit television pictures across the Atlantic.

NASA works on an Early Bird.

NASA works on an Early Bird.

Weekly Stargazers’ Rating: 4/26/09 – 5/2/09

Weekly Stargazers’ Rating | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

The stargaze rating for deep sky objects this week is excellent to good.  The Moon will be waxing during the week from nearly New to first quarter on Friday.  That means the Moon will be up in the early evening skies.

The moongaze rating for the week is also very good for the week.  We can watch as the terminator moves from the eastern limb to the middle of the Moon, revealing the crater relief along the line of the shadow.

Planet Watch: 4/26/09 – 5/2/09

Planet Watch | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

For a great website to locate the planets, go to www.nightskyinfo.com.  This site will tell you about the planets and give you a good star map to locate them.  116

Sunset Sky: (Sunset until 11 p.m.)

This week Mercury will be setting around 9:35 p.m. EDT.  Surprisingly, Mercury is fairly bright this week.  It is a magnitude 0.9 planet.  This is just 0.1 magnitude dimmer that Saturn.  It will be as high in the early evening sky this week as it will be all year long.  It will be in greatest elongation at 20 degrees on April 26th.  Remember that Mercury will circle the Sun two more times by the end of December so it will be seen in the morning and even on two more complete cycles.  The next cycle that it will become as high in the early evening sky as it is this week, will not happen until the end of December.
Saturn transits our sky at the same time in the evening, 9:40 p.m. EDT.  This makes Saturn a wonderful early evening sky object.  Shining in at a 0.8 magnitude, you should be able to see it fairly easily.  I mentioned earlier that it is just a little brighter than Mercury (0.1 magnitude) but what I did not say was that Saturn has twice the apparent diameter as Mercury and it is in a much darker part of the heavens than Mercury.  You will find that Saturn is visible in the night sky almost all night long, setting around 4:30 a.m. EDT.

Late Evening (11 p.m. until 4 a.m.):

As was just mentioned, Saturn is still up in the late night.  In fact, it is just about all there is to see in the late night as far as planets go.

Predawn Sky:  (4 a.m. until sunrise)

Jupiter and Neptune rise around 3:00 a.m. EDT so you will be able to see them before sunrise.  Jupiter can be used as a nice pointer to locate Neptune if you have a pair of binoculars or a small telescope.

Uranus and Venus rise almost at the same time this week, around 4:30 a.m. EDT. If the light from Venus is not too bright, you can use Venus as a pointer to help you locate Uranus. Venus will be shining in at a magnitude -4.7 on Saturday, May 2nd.  This will be the brightest that Venus will be during its current orbit of the Sun.
Mars is the last planet to rise in the east this week.  It pops up from the horizon around 4:45 a.m. EDT.  By sunrise, you should be able to get a glimpse of it.

Satellite Watch: 4/26/09 – 5/2/09

Satellite Watch: Satellites of Magnitude 3.0 and brighter | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

Sunday, April 26, 2009:

Hubble Space Telescope (HST): 21:13 Hrs, 32Âş altitude in the S, rising from the SW, heading to the ESE, magnitude 2.6.

Monday, April 27, 2009:

Hubble Space Telescope (HST): 21:11 Hrs, 36Âş altitude in the S, rising from the WSW, heading to the ESE, magnitude 2.4.

Tuesday, April 28, 2009:

Hubble Space Telescope (HST): 21:09 Hrs, 38Âş altitude in the S, rising from the WSW, heading to the ESE, magnitude 2.4.

Wednesday, April 29, 2009

Resurs 01 Rocket Body: 05:14 Hrs, 89Âş altitude in the NNE, rising from the NNE, heading to the SSW, magnitude 2.8.
Hubble Space Telescope (HST): 21:07 Hrs, 38Âş altitude in the S, rising from the WSW, heading to the ESE, magnitude 2.4.
Lacrosse 4 Satellite: 22:19 Hrs, 57Âş altitude in the ENE, rising from the NNW, heading to the E, magnitude 2.8.
Lacrosse 2 Satellite: 22:19 Hrs, 76Âş altitude in the ESE, rising from the SSW, heading to the NNE, magnitude 2.4.
MetOp-A Satellite: 22:42 Hrs, 79Âş altitude in the E, rising from the SE, heading to the N, magnitude 2.9.

Thursday, April 30, 2009:

Hubble Space Telescope (HST): 21:06 Hrs, 36Âş altitude in the S, rising from the WSW, heading to the ESE, magnitude 2.5.

Friday, May 1, 2009:

Hubble Space Telescope (HST): 21:04 Hrs, 32Âş altitude in the S, rising from the WSW, heading to the SE, magnitude 2.7.
Lacrosse 2 Satellite: 21:28 Hrs, 42Âş altitude in the ENE, rising from the S, heading to the NE, magnitude 2.9.
Lacrosse 4 Satellite: 21:51 Hrs, 58Âş altitude in the ENE, rising from the NNW, heading to the SE, magnitude 2.8.

Saturday, May 2, 2009:

Lacrosse 2 Satellite: 21:52 Hrs, 71Âş altitude in the WNW, rising from the SSW, heading to the NNE, magnitude 2.8.

Moon Watch: 4/26/09 – 5/2/09

Moon Watch | Posted by Drew on Behalf of Dr. Bob.
Apr 26 2009

Tuesday (28th), the Moon will be in perigee, its closest distance to the Earth, (227,446 miles) at 2:25 a.m. EDT

Friday (1st), the Moon is in First Quarter at 4:44 p.m. EDT.

Special Feature: Lyrid Meteor Shower April 22nd

Fun Space Facts | Posted by Drew on Behalf of Dr. Bob.
Apr 19 2009

Wednesday morning, before sunrise, we have a chance to see a beautiful meteor shower.  The Lyrid Meteor Shower is caused by the Earth passing through the dusty tail of Comet Thatcher (C/1861 G1).  The grains of sand strike the Earth’s atmosphere and vaporize producing brilliant streaks of light, what we call a meteors or shooting stars.

With the Moon nearly New, the conditions are perfect for viewing this meteor shower.  There are only three things we need to see the meteors.  First, the sky must be clear, lately this has not been the case.  Secondly, you need to go to a fairly dark location to view them.  Lastly, you need to get up, out of bed, and go into the night to see them.  I feel this year may be just the year to see some pretty bright and exciting meteors.

For a good website to show you where they originate and some additional information go to:

http://spaceweather.com/meteors/lyrids/lyrids.html

In preparation of your meteor watching party, dress warmly, take along a nice folding chair or blanket to lie on.  It would not hurt to bring along some friends and hot chocolate.  This is a great time to bring a friend who might not be as familiar with the sky as you are so you can introduce them to the wonders you have discovered.  You can also bring some binoculars to view the sky between meteors.  Binoculars will not help you to see any meteors; they come and go in the blink of the eye but they will give you something else to observe.

Celestial Feature of the Week: M65 & M66 Pair of Galaxies

Celestial Feature of the Week | Posted by Drew on Behalf of Dr. Bob.
Apr 19 2009

This fine pair of galaxies can easily be seen through a pair of binoculars or small telescope.  I have chosen this pair because of where they lay in Leo the Lion.  If you have been looking in the night sky lately, you have noticed that Leo is on your meridian around 9:00 p.m. EDT.  That means it is nicely placed for most stargazers to observe during an early evening.

M65

M65

M65 and M66 are spiral galaxies, which are about 29 million light-years from us.  They appear to be about the same size (8’ x 3’) so they are large enough to be seen with very low power telescopes and binoculars.

M66

M66

To find this beautiful pair, look at the hindquarters of Leo the Lion.  They are just below (south) of the base of the right triangle, just below the star representing the right angle (Chort).  You will need good dark skies to observe it but with the Moon out of the way this week, you should have good luck at spotting it should the clouds part long enough for a star party.

Today in History: 4/19/09 – 4/25/09

Space History | Posted by Drew on Behalf of Dr. Bob.
Apr 19 2009

April 19, 1982: Astronauts Sally Ride and Guion Bluford became the first woman, and the first African-American, to be tapped for the US space mission.

Guion Bluford

Guion Bluford

Sally Ride

Sally Ride

April 19, 1993: Soviet / Russian cosmonauts made the 200th human space walk.  Manakov and Poleschuk relocated the drive unit for Mir’s solar panels, experiencing some difficulties, including loss into space of a handle used to operate Mir’s “crane”.

Mir and Atlantis

Mir and Atlantis

April 20, 1972:  The manned lunar module from Apollo 16 landed on the moon. Astronauts John Young and Charles Duke explored the moon surface the following day.

Duke on the Craters Edge

Duke on the Craters Edge

April 23, 1992: COBE satellite findings show a structure in cosmic background radiation.

April 24, 1962: MIT achieved the first satellite relay of a television signal, between Camp Park, California, and Westford, Mass.

April 24, 1970: The Peoples Republic of China launched its first satellite — known as China 1 or Mao 1 — to Earth orbit on its own “Long March” space rocket. The 390-lb. electronic ball floated around the Earth blaring the patriotic song The East Is Red.  The launch made China the fifth nation with a space rocket. Before that first successful launch, the Chinese may have sustained a launch failure in 1969. They may have suffered three failures in 1974 and another in 1979.

Long March Rocket launch.

Long March Rocket launch.

April 24, 1990: the space shuttle Discovery (STS-31) launched from Cape Canaveral, carrying the Hubble Space Telescope.  The telescope was deployed on the following day April 25th.

STS-31 -  Discovery deploys the Hubble Telescope.

STS-31 - Discovery deploys the Hubble Telescope.

April 25, 1983: the spacecraft Pioneer 10 crossed Pluto’s orbit, speeding on its endless voyage through the Milky Way.

April 25, 1990: Hubble Space Telescope’s birthday.  Hubble Space Telescope was deployed from STS-31 Discovery launching a new era in observational space exploration.