WISE Shows us Infrared Views of Time and Space
Posted: October 27, 2010 Filed under: Caroline Herschel, constellations, entertainment, NASA's Wide-field Infrared Survey Explorer, NGC 253, Sculptor constellation, September 2010, spiral galaxies, star evolution, the Sculptor Galaxy, the Silver Coin Galaxy, William Herschel, WISE | Tags: astronomers, astronomy, Caroline Herschel, Journey to the Beginning of Space and Time, NASA, NASA's Wide-field Infrared Survey Explorer, NGC 253, Sculptor constellation, sister of astronomer William Herschel, South Polar Group, the Sculptor Galaxy, the Silver Coin Galaxy, WISE Leave a comment »
WISE uses four infrared detectors to view the Sculptor Galaxy
This is why they call NGC 253 the Silver Coin Galaxy
Dance Across the Night Sky with Cassiopeia the Queen
Posted: October 24, 2010 Filed under: Alpha Cassiopeiae, American Astronomical Society, astronomers, Astronomical Societies, astronomy, astronomy equipment, Beta Cassiopeiae, binoculars, Charles Messier, constellations, entertainment, Gamma Cassiopeiae, John Hopkins University, M 103, M 52, Messier catalogue, NASA, National Solar Observatory, New General Catalogue, October 2010, Ptolemy, Royal Astronomical Society, spiral galaxies, telescope accessories, telescopes, the Milky Way galaxy, the Universe | Tags: Alpha Cassiopeiae, Beta Cassiopeiae, Cassiopeia the Queen, constellations in the northern sky, constellations viewable in autumn's northern sky, Gamma Cassiopeiae, Halloween star treats, Journey to the Beginning of Space and Time, M 103, M52, NGC 129, NGC 581, NGC 7654, Ptolemy, time machine to the stars 2 Comments »
This star map gives you an idea of the stars in and around Cassiopeia the Queen
Cassiopeia the Queen is one of the first northern deep sky objects we’ll view during our “Journey to the Beginning of Space and Time”. Cassiopeia the Queen is easily recognizable in autumn’s night sky using her characteristic W or M shape form and she was one of the 48 constellations originally listed by the 2nd century Greek astronomer Ptolemy during his observations of the night sky. Today, Cassiopeia the Queen is one of 88 constellations recognized by modern star gazers in the night sky, and the abundance of magnificent open star clusters within her arms provides viewers with a chance to see a variety of outstanding celestial objects that have been entertaining star gazers for thousands of years.
Five stars outline Cassiopeia's characteristic W shape
Cassiopeia the Queen is a familiar sight for modern astronomers and star gazers in the mid-northern latitudes of planet Earth, and is often one of the first constellations in the northern sky beginning star gazers journey to view. Board your time-machine-to-the-stars near the end of October, or the beginning of November, and take the family on a journey through time and space to visit Cassiopeia the Queen. A visit with Cassiopeia the Queen will open a child’s mind to the possibilities of the universe, before them, and your wife will be able to tell her friends that you took her out last night.
8x50 astronomical binoculars will reveal about 12 stars nestled in among the collective glow of other stars to faint to resolve
One of the best open star clusters you can view with the naked eye is 6.5 magnitude NGC 129, a large, bright, open cluster of stars 8×50 astronomical binoculars will reveal to have six to twelve brighter stars nestled within the collective glow of a field of stars to faint to resolve using binoculars. You should see about 35 celestial bodies in this region of space and time 5,200 light years distant from your position on the Earth. Look toward the north of two 9th magnitude stars, near the center of NGC 129, and you’ll find the Cepheid variable DL Cassiopeiae. DL Cassiopeiae will fluctuate between 8.6 and 9.3 magnitude, over the course of an eight-day cycle.
The central star in Cassiopeia’s characteristic W is Gamma Cassiopeiae, a prototype for a class of irregular variable stars believed to be rapidly spinning type-B celestial bodies often fluctuating by as much as magnitude 1.5 or more, Gamma Cassiopeiae will flicker between 2.2 and 3.4 magnitude as you watch her nightly dance and this star at maximum brightness outshines both Alpha Cassiopeiae and Beta Cassiopeiae. Astronomers believe these apparent fluctuations are due to a decretion disc around this star resulting from the rapid spinning of the star, which results in some of the star’s mass forming a decretion disc. Gamma Cassiopeiae is also a spectroscopic binary star with an orbital period of about 204 days and astronomers believe Gamma Cassiopeiae’s companion star is about the same relative mass as Sol. Part of a small group of stellar sources in the night sky that beam of X-ray radiation about 10 times higher than the X-rays emitted from other type-B stars across the cosmos, Gamma Cassiopeiae exhibits both short-term and long-term cycles of x-ray emission. Star gazers should also be able to view Gamma Cassiopeiae as an optical double star, with a faint magnitude 11 companion star, about 2 arc seconds distant from Gamma Cassiopeiae.
Ancient star gazers in China called Gamma Cassiopeiae Tsih, which loosely translates as “the whip”, but no references have been found in Arabic or Latin texts of Gamma Cassiopeiae being referred too using a different name. Modern star gazers refer to Gamma Cassiopeiae by a number of different designations, including 27 Cassiopeiae, HR 264, HD 5394, and others. Modern astronauts often use Gamma Cassiopeiae as a star-guide because it’s a relatively bright celestial object and in previous space missions this star was used as an easily recognizable navigational reference point in the night sky.
M103 (NGC 581) will reveal about 25 magnitude 10 or fainter stars
M103 (NGC 581) is the first of two Messier objects in Cassiopeia’s arms viewable through a six-inch time-machine-to-the-stars and should appear as about three dozen stars grouped in a triangular area 6′ across. A fairly compact open cluster, M103 will be 1 degree east of Delta Cassiopeiae, and is the left bottom star of Cassiopeia’s characteristic W shape marking her throne in the night sky. Pierre Mechain was first given credit for seeing this open cluster in the night sky in 1781. Star gazers using 8×50 binoculars will see about 25 magnitude 10 or fainter stars in their view and a string of four stars immediately to M103′s southeast, which adds to the beauty of viewing M103, significantly.
M 52 (NGC7654) is one of the richest open clusters to view north of the celestial equator
The second Messier object in Cassiopeia catalogued by Messier is M52 (NGC 7654), you can locate M52 by drawing a line from Alpha Cassiopeiae through Beta Cassiopeiae, and then extending your line an equal distance to M52. An 8-inch time-machine-to-the-stars will reveal about 75 stars in the night sky clumped in various patterns along the edge of the Milky Way that aren’t lost among the background points of light behind these stars. One of the richest open clusters in Cassiopeia’s arms and north of the celestial equator, Messier made note of M52 in his catalogue in 1774. This open cluster will appear as a nebulous mass of about 100 stars in 8×50 astronomical binoculars, with a few individual stars that you can resolve a little better. Star gazers looking for a little extra should look to the north of M52 to find Harrington 12, a wide triangular looking asterism containing about a dozen 5th to 9th magnitude stars, which will appear spectacular in low-power astronomical binoculars.
Journey less than 3 degrees south of Delta Cassiopeiae to find the spectacular Owl Cluster (NGC 457), a celestial object ancient star gazers could plainly see in the north night sky, the Owl Cluster’s wings will be clearly viewable using a 4-inch time-machine-to-the-stars. Star gazers can also locate Delta Cassiopeiae by using 5th magnitude Phi Cassiopeiae and 7th magnitude HD 7902, which lie to the southeast of the Owl Cluster. The Own’s eastern wing is a line of four bright stars, while the western wing is composed of two pairs of stars arranged in a long rectangle. The brightest star in the Owl Cluster will shine at 8.6 magnitude and will appear a little orange in color in star gazers.
Cassiopeia the Queen reigns in autumn's night sky
Collisions in Space
Posted: October 24, 2010 Filed under: ARTEMIS, astronomers, astronomy, Earth, entertainment, Magnetosphere, meteorites, NASA, Sol, The Earth, the Moon, the solar system, the solar wind, the Universe, THEMIS-B | Tags: ARTEMIS, astronomer, astronomy, collisions in space, Magnetosphere, meteorites, Moon, NASA, solar wind, spacecraft, THEMIS Leave a comment »
Something might have hit THEMIS-B
Considering the volume of bodies circling in the solar system one might think that collisions between bodies in the solar system is commonplace, but in fact collisions between bodies circling in the solar system are relatively uncommon. This is what makes a recent report by NASA of a possible collision of one of their spacecraft with a meteorite a highlight of sorts, or at least something relatively unusual. NASA reported a possible collision between a meteorite and part of the sensitive instrumentation on board their THEMIS-B spacecraft, which is one of the two ARTEMIS spacecraft, at 0605 UT on October 14. Apparently, the flight dynamics data collected on THEMIS-B indicated that it might have been struck by a meteorite, which likely means the meteorite made a slight change in the flight path of the spacecraft. According to NASA, everything is still a go with THEMIS-B’s insertion into Lissajous orbit, and up coming simultaneous measurements of particles and the electric and magnetic fields in two different locations, using both ARTEMIS spacecraft. This will provide astronomers with the first three-dimensional look at how energetic particle acceleration happens near the Moon’s orbit, in the solar wind, and in the distant magnetosphere.
Deep Impact Shows Comet Scientists Something New
Posted: October 23, 2010 Filed under: American Astronomical Society, astronomers, Astronomical Societies, astronomy, comet Hartley 2, comets, Deep Impact, Earth, EPOXI mission, Goddard Flight Center, International Astronomical Union, John Hopkins University, NASA, NASA's Deep Impact spacecraft, National Solar Observatory, Royal Astronomical Society, Sol, The Earth, the solar system | Tags: astronomers, astronomy, comet Hartley 2, comets, Deep Impact, EPOXI mission, NASA Leave a comment »
- The EPOXI mission is just the first step
Deep Impact approaches comet Hartley 2 and will arrive at its nearest location on November 4
NASA’s EPOXI mission is currently on a journey to comet Hartley 2 and Deep Impact as this mission is more commonly referred too will arrive at its nearest spot to this icy world on November 4. NASA was using imagers on Deep Impact during the days between September 9-17 to get a view of comet Hartley 2 before the spacecraft arrives on location and the things they saw has NASA’s comet scientists shaking their heads. Apparently, comet scientists observed the characteristic increase in the release of cyanide associated with comets as they travel through the inner solar system, by a factor of five or six times during this observation period in September. What they didn’t see was the expected increase in dust emissions due to this five fold increase in the release of cyanide, which is something new according to comet scientists, who are now busy trying to figure out what they actually saw.
Why would the difference be so important to comet scientists as Deep Impact approaches comet Hartley 2? Scientists hate unknown parameters being suddenly thrown into their well calculated plans and this discovery certainly could affect the mission in ways we’ll possibly never hear about. Where did the dust go? The dust obviously didn’t go anywhere and is still close to comet Hartley 2, which could effect the quality of the view observers will get of Hartley 2. This will especially be true for observers on Earth, who now that they know about this fact can certainly take this fact into consideration. Otherwise, this fact is going to skew your observations and your interpretation of what you’re actually seeing when trying to view comet Hartley 2 from Earth. Certainly, this isn’t likely to seriously affect the mission as a whole, and Deep Impact will surely get some spectacular pictures of comet Hartley 2 as it approaches and recedes from the sun.
The interesting thing about comets releasing significant amounts of cyanide is that cyanide is a carbon-based molecule that certainly could have been brought to Earth on comets like Hartley 2 billions of years in the past. Comets haven’t changed since this time and have been hitting the Earth and releasing cyanide since this time, which brings up interesting questions that NASA is hoping the EPOXI mission and follow up missions to other comets is going to answer in the years ahead.
Navigating the Universe Using the Stars as Your Guide
Posted: October 23, 2010 Filed under: altitude-azimuth coordinate system, American Astronomical Society, astronomers, Astronomical Societies, astronomy, Earth, entertainment, equatorial coordinate system, Goddard Flight Center, International Astronomical Union, John Hopkins University, NASA, National Solar Observatory, Royal Astronomical Society, sky coordinate systems, space history, star catalogues, the day and night cycle of Earth, The Earth, the Earth's orbit, the Earth's rotation, the months | Tags: altitude-azimuth coordinate system, astronomers, astronomy, azimuth, Big Dipper, Celestial cartographers, celestial equator, celestial globes, celestial sphere, declination, equatorial coordinate system, Journey to the Beginning of Space and Time, night sky, right ascension, star gazers, zenith 1 Comment »Astronomers use coordinate systems to plot the position of stars in the night sky
Looking up into the night sky you probably wonder how ancient star gazers were able to navigate using the stars in the night sky as their guide. One of the first things ancient star gazers did to help them navigate the night sky, and the surface of the Earth, was to create a coordinate system to pinpoint relative positions of the stars in the night sky in relation to one another.
Looking upward into the night sky, imagine the sky above you as a sphere of infinite size, centered on the Earth. This technique works in general because distances to the stars above you is not discernible using your naked eye, so the objects you see above you in the night sky all appear to lie on a great sphere at an infinite distance in relation to you.
Modern astronomers use two coordinate systems to determine the relative positions of objects in the night sky; the altitude-azimuth coordinate system and the equatorial coordinate system. We will talk a little about both coordinate systems currently being used by modern astronomers to help them plot the positions of the objects they view in the night sky and using celestial objects you view on your “Journey to the Beginning of Space and Time” to navigate your way through the universe.
The altitude-azimuth system works fine
In the altitude-azimuth coordinate system altitude indicates the number of degrees from the horizon to the object in the night sky you’re viewing, and ranges from 0 degrees at the horizon to 90 degrees at the zenith above you. Modern astronomers measure azimuth along the horizon from north to east, to the point where a line passing through the object in the night sky intersects the horizon at a right angle, and azimuth varies between 0 degrees and 360 degrees. Astronomers also subdivide each degree of azimuth into 60 arcminutes and each archminute into 60 arcseconds, which helps to further subdivide the immense distances between each degree of measurement in the night sky.
Navigating the night sky becomes a lot easier using a coordinate system
The altitude-azimuth coordinate system doesn’t take into account the rotation of the Earth, though, and astronomers have solved this problem by fixing coordinates to the celestial sphere you imagine above you in the night sky. Celestial cartographers have created “celestial globes”, similar to the globes of the Earth that cartographers have devised for centuries to show the Earth and all of its features. On these celestial globes you’ll find terms like the celestial equator and North and South celestial poles.
The equatorial coordinate system works even better for navigating the night sky
In the equatorial coordinate system astronomers use two aspects called declination and right ascension to fix a star’s position on the celestial sphere you picture above you. Declination is analogous to Earth’s latitude and represents the angle between the object you’re viewing in the night sky above you and the celestial equator. Declination varies between 0-90 degrees, North and South of the celestial equator, and is measured in degrees, arcminutes, and arcseconds, while a minus sign is used to designate objects south of the celestial equator.
The equatorial system is more widely used today
The lines of circles that run through the celestial poles perpendicular to the celestial equator represent the hour circle of objects in the night sky above your head, and are analogous to the meridian of longitude on the Earth. In order to fix an objects position in the celestial sphere above you we’ll also need to set the zero point of the longitude coordinate of the object, which astronomers call the objects right ascension. In order to accomplish this we need an intersection point between the Earth’s equator and its orbital plane, the elliptic. Astronomers call this intersection point the vernal equinox and the sun appears to travel through the intersection point annually around March 21, as it moves South to North crossing the celestial equator.
The angle that lies between the vernal equinox and the point where the hour circle of the celestial object in question intersects the celestial equator is the right ascension of the object you see in the night sky. Right ascension is measured in hours (h), minutes (m), and seconds (s), from west to east, and the vernal equinox is zero-hour. There are about 24 hours in each day on the Earth, so each hour of right ascension in the night sky corresponds to 15 degrees of longitude.
The movement of the Earth and the objects in the night sky above you mean the appearance of the night sky is dynamic in nature, so celestial objects will appear to circle the celestial poles as you watch the night sky. A star with a greater distance from a celestial pole than your latitude will only be visible to you during a portion of its orbit. In this case the star will rise in the east and set in the west. Stars that are always above your horizon are circumpolar for your latitude and you’ll see these stars for their entire orbit.
The Earth’s rotation and the movement of the stars also means the constellations in the night sky above you travel slowly westward during the year. Pinpoint a star you know well in the night sky at exactly 9 P.M. tonight. This same star will be in the exact same position in the night sky tomorrow night, only 4 minutes earlier, at 8:56 P.M. Check the time this same star is in the same position on the next night and you’ll see this occurs at 8:52 P.M.
Do a little math and you’ll verify that in one month this set up would leave the stars in the night sky 2 hours out of phase with our first positional reading in the night sky for this same star. In 3 months, generally one season, the stars in the night sky above you will have traveled a quarter of the way across the night sky. After four seasons, this would bring the star in question back to the same position in the night sky as twelve months before.
One way to estimate distances in the night sky above you and give yourself a tool to help you navigate the universe on your “Journey to the Beginning of Space and Time” is to use star pairs in the night sky as your guide. Star travelers can learn by using star pairs in the Big Dipper, for example.
On a star atlas you’ll see objects on the map described as 12 degrees from such-and-such a star. If you study the separations between the stars of well-known stars, like the ones in the Big Dipper, you can train your eyes to visually estimate distances between stars. Take a look at a star chart of the Big Dipper and you’ll see that Alpha Ursae Majoris is about 5 degrees separated from Beta Ursae Majoris. Delta Ursae Majoris, on the other hand, is 10 degrees from Beta Ursae Majoris, while Beta Ursae Majoris is about 25 degrees from Eta, and this trend continues. Star gazers can learn to visually estimate graduations less than 1 degree in the night sky as well. Use the Full Moon, which measures 1/2 degree across. This distance is close to the distance between two stars in Scorpio’s stringer and if you use it as your measuring stick, you’ll see other pairs with about the same separation in the night sky above you. Search the night sky as you “Journey to the Beginning of Space and Time” for road markers and celestial objects you can use to navigate your way to infinity. This will help you find your way back from your trip and navigate the night sky to the objects you want to view.
The Earth’s Movements: Spaceshipearth1′s Orbit
Posted: October 17, 2010 Filed under: astronomers, astronomy, Earth, Einstein, entertainment, General Relativity, NASA, scientists, Sol, Special Relativity, the day and night cycle of Earth, The Earth, the Earth's orbit, the Earth's rotation, the Milky Way galaxy, the months, the seasons of Earth, the solar system | Tags: astronomers, astronomy, Earth's movements in the universe, Earth's orbit, Earth's rotation, the day and night cycle of Earth, the seasons of Earth Leave a comment »
The combination of the Earth's movements help to create the seasons and environment of Spaceshipearth1
The Earth’s orbit around Sol and other things
A little seasoning anyone!
The Earth beneath you and the night sky above you are both moving relative to each other and you, and the universe around you. The Earth not only spins counterclockwise on its axis, but also orbits Sol about once every 365 spins on its axis, give or take a few minutes, in a counterclockwise direction. Speeding through space and time at an impressive 100,000 km/hr (60,000 miles/hr), around 100 times faster than a speeding bullet, faster than the launch speed for any known spacecraft and certainly faster than Superman, the Earth’s orbit isn’t a perfect circle. In fact, the distance of the Earth to Sol during its transit differs significantly at different times, due to this non-circular orbit, but on average the distance between Earth and Sol is about 150 million kilometers (93 million miles). This distance astronomers call an astronomical unit, or AU, and this unit is used by astronomers as a measuring stick of sorts, only on a bigger scale than the mile or kilometer.
The axis of the Earth during its orbit is also tilted about 23 1/2 degrees from the line perpendicular to the flat plane traced out by the Earth’s orbit around Sol. This flat plane astronomers call the ecliptic plane and in reality this axis tilt has no meaning in Einstein’s space and time and is only useful in relation to the ecliptic plane. In Einstein’s universe, the notion of tilt by itself has no meaning in space and time, where up and down are related to away from the center of the Earth (or any body with mass) and toward the center of mass, respectively.
The Earth’s axis also continues to point in the same general direction throughout Earth’s orbit of Sol. This direction is toward Polaris, often called the North Star by travelers and navigators, and lies within 1 degree of the north celestial pole, which makes it useful for navigating on the surface of Earth. This direction closely marks the direction of due north in the night sky and the altitude of Polaris is nearly equal to the latitude of an observer on the surface of Earth. Navigators and star gazers have used these facts for thousands of years to determine direction and location on the Earth’s surface and travel from one destination to another.
The changing position of Earth during the 365 days it takes the Earth to complete one orbit also results in the night sky above your head changing nightly. Sol appears to move against a background of distant stars in the 88 constellations in the Milky Way above you. The 12 constellations along the ecliptic plane star gazers refer too as the constellations of the Zodiac, but a thirteenth constellation, Ophiuchus lies partially on the ecliptic plane, as well.
The combination of the rotation of the Earth on its tilted axis and orbit around Sol, also helps create the seasons we experience on Spaceshipearth1. In future articles, we’ll talk about the seasons of Earth, the meaning this has for life on Earth, and how this relates to the study of the movements of the exo-planets humans have, so far, viewed during the human “Journey to the Beginning of Space and Time”.
The Spinning Earth
Posted: October 16, 2010 Filed under: American Astronomical Society, astronomers, Astronomical Societies, astronomy, Earth, entertainment, Goddard Flight Center, International Astronomical Union, John Hopkins University, NASA, National Solar Observatory, Royal Astronomical Society, scientists, Sol, The Earth, the Earth's orbit, the Earth's rotation, the months, the solar system | Tags: astronomy, Journey to the Beginning of Space and Time, North Pole, Sol, South Pole, SpaceshipEarth1, the daily cycle of the Earth, the Earth, the Earth's axis, the Earth's rotation, the Earth's speed of rotation 1 Comment »
The earth rotates on its axis in about 24 hours, give or take a few minutes
The Earth rotates on its axis each day
The Earth goes through a number of different positions which astronomers have measured
Looking upward at the night sky you don’t actually feel the relative motion of the Earth beneath you, despite this you’re rotating at about 1000 km/hr, depending on where you’re situated on the Earth. Standing on the exact center of the North Pole, your relative speed of rotation is much less than if you were standing on the equator, and the closer you’re to the equator, the faster the Earth beneath you is moving. Standing on the equator the Earth beneath you is rotating at about 1,670 km/hr, move half-way to the North or South Pole, and the speed of rotation of the Earth decreases significantly to about 1,275 km/hr, and once you are standing on the exact North or South Pole the Earth isn’t rotating.
The rotation of the Earth on its axis has consequences for the planet and all life existing on the spaceshipearth1. The daily rotation of the Earth on its axis creates the night and day cycle we all rely on, and this motion combined with the spaceshipearth’s orbit around Sol produces the seasonal cycles we all experience during life on Earth. We’ll talk about the Earth’s daily cycle and what this means for life on Earth in future articles.
The Moving Universe
Posted: October 16, 2010 Filed under: American Astronomical Society, astronomers, Astronomical Societies, Earth, Einstein, entertainment, General Relativity, Goddard Flight Center, International Astronomical Union, John Hopkins University, NASA, National Solar Observatory, October 2010, Royal Astronomical Society, scientists, Sol, Special Relativity, The Earth, the Earth's orbit, the Earth's rotation, the Milky Way galaxy, the months, the planets, the Universe | Tags: Einstein, General Relativity, Journey to the Beginning of Space and Time, Milky Way Galaxy, Sol, SpaceshipEarth1, Special Relativity, the Earth, the Earth's movement through the Milky Way, the Earth's orbit, the Earth's rotation, the solar system, universe Leave a comment »
The Earth is moving relative to everything else in the universe
Everything on your “Journey to the Beginning of Space and Time” is moving relative to everything else in the universe
The Earth rotates on its axis
A True Pioneer of the Human Journey to the Beginning of Space and Time
Posted: October 13, 2010 Filed under: American Astronomical Society, astronomers, astronomy, Goddard Flight Center, International Astronomical Union, John Hopkins University, Luna 24, Mare Crisis, Mare Marginis, NASA, National Solar Observatory, October 2010, Robert Goddard, rocket scientists, Royal Astronomical Society, Russian Space Agency, space history, the months, the Moon, the Sea of Crises, the Sea of the Margin | Tags: crater Goddard, craters on the Moon, Journey to the Beginning of Space and Time, Luna 24, Mare Crisium, Mare Marginis, Moon's eastern limb, Robert Goddard, the Moon, the Moon in October, the Sea of Crises, the Sea on the Margin, things to see on the Moon Leave a comment »
Crater Goddard arcs past the Moons' eastern limb during a few nights in October, beginning on the 10th
The Moon dances, spins and twirls and crater Goddard arcs past your view
On the 10th of October you'll see lots of real estate between the Moon's eastern limb and Mare Crisium
Star gazers can pay respects to a true pioneer of human space travel Robert Goddard beginning on the night of October 10th, by taking a journey to the Moon to view the crater named after this gentleman of astronomy. Your view of the Moon’s crescent will show plenty of open landscape between the Moon’s eastern limb and Mare Crisium on this night.
A large oval plain encompassing an area 270 miles wide by 350 miles long, with the long side running east to west, Mare Crisium will appear different on this night because of the foreshortening of the lunar globe. Mare Crisium also stands alone on the surface of the Moon and isn’t interconnected with the other maria you’ll view on the Moon’s surface during your “Journey to the Beginning of Space and Time”. The last place on the Moon’s surface to be visited by mankind, Mare Crisium, or the Sea of Crises, was host to the unmanned soviet spacecraft Luna 24 in 1976. Look for dark patches along the Moon’s limb on October 10th, which is actually hardened lava of Mare Marginis, the Sea on the Margin, and find the short white arc just beyond the eastern shore of the sea. This short white arc is in fact the illuminated rim of crater Goddard. Watch as Goddard arcs past the Moon’s eastern limb over the next few nights and you’ll get a good lesson in how the Earth’s satellite moves as the Moon’s eastern limb rotates away from Earth.
On October 15th, Goddard will appear in profile and you should see the rim of this crater poking outward, like two towering peaks framing a darker interior. On October 18th, Goddard will have disappeared over the limb and only about half of Mare Marginis will be viewable. On October 22nd, the Moon will be in full phase at 9:37 P.M. EDT, and only an outline of the shoreline of Mare Marginis will be visible. By this time Mare Crisium will appear much closer to the limb and is prominent in your view of the Moon.
Why does Mare Crisium appear closer and what causes this visual sleight-of-hand? The Moon actually spins at a pretty constant rate, generally completing one rotation on it axis each month. In the same time frame, however, the Moon orbits the Earth on an elliptical path, and this means the Moon’s speed of rotation will vary. This allows viewers to see a few degrees beyond the normal limb of the Moon during specific time frames of the lunar cycle, which is an effect astronomers refer too as the libration of the Moon.
To be a Planet, or Not to be a Planet?
Posted: October 8, 2010 Filed under: American Astronomical Society, astronomers, Astronomical Societies, astronomy, Earth, entertainment, Goddard Flight Center, International Astronomical Union, John Hopkins University, Jupiter, Mars, Mercury, Michael Brown, NASA, National Solar Observatory, Neptune, Pluto, Royal Astronomical Society, Saturn, Sol, The Earth, the planets, the solar system, Uranus, Venus | Tags: asteroids, astronomers, astronomy, Caltech, International Astronomical Union, Journey to the Beginning of Space and Time, Jupiter, Kuiper Belt, Mars, Mercury, meteorites, Michael Brown, Neptune, Planet X, Pluto, Saturn, science, space, the Earth, the planets, the solar system, Uranus, Venus, Xena the warrior goddess 1 Comment »
The largest Kuiper Belt objects compared
How much bigger is Planet X than Pluto? Astronomers have measured the brightness and distance of Planet X from Sol, as compared to objects of known brightness in the solar system. Based on their data and calculations, astronomers believe Planet X to be bigger than Pluto, but just how much bigger has yet to be firmly etched in stone by the various astronomical societies and agencies tasked with determining if Planet X is indeed bigger than Pluto and by how much. This fuzzy-news has pushed Pluto into tenth place in the nine planet race in the solar system and into second place in the size ranking of the objects in the Kuiper Belt and astronomers, and star gazers have only searched a small percentage of the Kuiper Belt for objects bigger than Pluto.
Will bigger objects than Planet X be discovered in the Kuiper Belt or somewhere on the outer fringes of the solar system? The first Kuiper Belt objects were viewed by star gazers and astronomers in the early 1990s, but since this time larger and larger objects have been located in the Kuiper Belt. In 2002, an object half the size of Pluto was discovered floating in the Kuiper Belt, which astronomers named Quaoar. Just two years later, 2004DW and Sedna were discovered, each respectively two-thirds and three-quarters the size of Pluto. It wouldn’t be surprising, therefore, if star gazers and astronomers were to find an even larger object floating in the Kuiper Belt, than Planet X at some point in the human “Journey to the Beginning of Space and Time”.
Hubble has given us our best views of Pluto, so far. This photo shows Charon as well.
Compare the various sizes of the planets as you pass by
A distance object at best, Pluto looks quiet and serene here
