Ask An Amateur Astronomer
Bringing Astronomy to the general public.
Red Moon in June
Jun 6th
After the moon got super huge last March 2011, this coming June 16 2011, the moon will once again be spectacular to watch as it turns red because of the total lunar eclipse. Amazing, huh!! The first of the two eclipses of 2011 will occur on the said date and it will start at around 1:25AM and will end at around 7AM but the fun part where it turns red will be on its totality at around 4AM.
So, why does the moon turn red during a lunar eclipse?
During a total lunar eclipse, the Earth blocks the Sun’s light from reaching the Moon. Astronauts on the Moon would then see the Earth completely eclipse the Sun. (They would see a bright red ring around the Earth as they watched all the sunrises and sunsets happening simultaneousely around the world!) While the Moon remains completely within Earth’s umbral shadow, indirect sunlight still manages to reach and illuminate it. However, this sunlight must first pass deep through the Earth’s atmosphere which filters out most of the blue colored light. The remaining light is a deep red or orange in color and is much dimmer than pure white sunlight. Earth’s atmosphere also bends or refracts some of this light so that a small fraction of it can reach and illuminate the Moon.
The total phase of a lunar eclipse is so interesting and beautiful precisely because of the filtering and refracting effect of Earth’s atmosphere. If the Earth had no atmosphere, then the Moon would be completely black during a total eclipse. Instead, the Moon can take on a range of colors from dark brown and red to bright orange and yellow. The exact appearance depends on how much dust and clouds are present in Earth’s atmosphere.
So, how do we observe this?
Unlike solar eclipses, lunar eclipses are completely safe to watch. You don’t need any kind of protective filters. It isn’t even necessary to use a telescope. You can watch the lunar eclipse with nothing more than your own two eyes. If you have a pair of binoculars, they will help magnify the view and will make the red coloration brighter and easier to see. A standard pair of 7×35 or 7×50 binoculars work fine. Remember to dress warmly and enjoy the spectacle!
Amateur astronomers can actually make some useful observations during total eclipses. It’s impossible to predict exactly how dark the Moon will appear during totality. The color can also vary from dark gray or brown, through a range of shades of red and bright orange. The color and brightness depend on the amount of dust in Earth’s atmosphere during the eclipse. Using the Danjon Brightness Scale for lunar eclipses, amateurs can categorize the Moon’s color and brightness during totality.
Another useful amateur activity requires a telescope. Using a standard list lunar craters, one can careful measure the exact time when each crater enters and leaves the umbral shadow. These crater timings can be used to estimate the enlargement of Earth’s atmosphere due to airborne dust and volcanic ash.
Of course, an eclipse of the Moon also presents a tempting target to photograph. Fortunately, lunar eclipse photography is easy provided that you have the right equipment and use it correctly. See MrEclipse’s Picks for camera, lens and tripod recommendations. For more photographs taken during previous lunar eclipses, be sure to visit Lunar Eclipse Photo Gallery.
With these basic know-hows, always remember that you will not experience the maximum enjoyment if you are alone. So go, spread the news and together, let’s enjoy this dazzlimg moment. :)
*Note: All times and dates mentioned in this article are applicable in UT + 8*
Courtesy:
http://www.mreclipse.com/Special/LEprimer.html
http://journeytothestars.wordpress.com/tag/june-15-2011-total-lunar-eclipse/
Biggest Full Moon in 19 Years
Mar 14th
Yeah, you read the title correctly, another spectacle brought to you by the wondrous night sky will take place this Saturday, March 19, 2011 at approximately 6:10PM.
The date marks this year’s lunar perigee, the point in the moon’s orbit at which it is closest to Earth. It’s the moon’s elliptical orbit that’s responsible for the differences in distance between the moon and Earth (the opposite, the point at which the moon is farthest from the Earth, is called the lunar apogee). This month’s perigee will leave the moon, says Steve Owens at Dark Sky Diary, about 8 percent closer to Earth than usual, and about 2 percent closer to Earth than the average lunar perigee. In fact, it’ll be the closest positioning since 1992. The full moon could appear up to 14% bigger and 30% brighter in the sky, especially when it rises on the eastern horizon at sunset or is provided with the right atmospheric conditions.
At a distance of 221,567 miles, this phenomena, called “The Supermoon” is associated to various catastrophic events such as the recent earthquakes and tsunamis in Japan, Hurricane Katrina in 2005, the Indonesian earthquake in 2005 and the Australian flooding in 1954. Now, is this really true? Quoting some of the scientists, here’s what they have to say:
- John Bellini, a geophysicist at the U.S. Geological Survey: “A lot of studies have been done on this kind of thing by USGS scientists and others. They haven’t found anything significant at all.” The tides will pull a bit higher, but earthquakes are almost completely unaffected and volcanoes are not likely to show unusual behavior.
- John Vidale, a seismologist at the University of Washington in Seattle, said “Practically speaking, you’ll never see any effect of lunar perigee. It’s somewhere between ‘It has no effect’ and ‘It’s so small you don’t see any effect.’”
- Dr. Tim O’Brien, a researcher at the Jodrell Bank Centre for Astrophysics at the University of Manchester, said: “The dangers are really overplayed. You do get a bit higher than average tides than usual along coastlines as a result of the moon’s gravitational pull, but nothing so significant that will cause a serious climatic disaster or anything for people to worry about.”
How’s that for proof that the supermoon is not a thing to be scared of rather, it is a spectacle to be enjoyed. So come March 19, 2011 at around 6:10 PM, go out, gather your friends and take your time to witness the total awesomeness that is, the SUPERMOON!
http://adventofdeception.com/extreme-supermoon-march-19
http://psychedelicadventure.blogspot.com/2011/03/biggest-full-moon-in-two-decades-19th.html
http://www.popsci.com/science/article/2011-03/biggest-full-moon-20-years-almost-certainly-wont-cause-huge-natural-disaster
Night Sky Attraction for December 2010
Nov 30th
Sky highlights of December 2010 include meteor showers, a total lunar eclipse, winter solstice, Jupiter and some pretty star clusters.
Its Christmas season, the air is getting colder, and the nights are getting longer. Northern Hemisphere nights will be at their longest and Southern Hemisphere nights will be at their shortest on December 21 winter solstice, when the Sun reaches its farthest distance south of the celestial equator.
December has to offer two meteor showers, the famous Geminids and Ursids. The Geminids, one of the best and must-not-miss meteor showers, peaks from late night of December 13 until dawn of December 14. Watch out for these meteors or popularly known as “shooting stars” as they seemingly radiate from the constellation Gemini, the Celestial twins, where the name of the shower apparently came from. You can locate Gemini northeast of the Great Hunter Orion. At its best, Geminids can display about 60 or more meteors per hour (a stunningly one meteor per minute!). These meteors come from the asteroid named 3200 Phaethon. The Ursids, however, has a less showy display and peaks on December 22. Averaging about 9 meteors per hour, they seem to originate from the constellation Ursa Minor where you can also find the famous Small Dipper and Polaris the North Star. Lie down outside, relax, and watch the beautiful display of these meteor showers, also don’t forget to bring your long wish list for Christmas!
A total lunar eclipse will occur on December 21 when the moon is full and enters completely in the darkest part of our planet’s shadow. This is a great display where we can see the Moon in coppery red glow. However, observers from the Philippines will be able to witness the final phase of the eclipse for the reason that the eclipse will enter its greatest eclipse at 4:17PM Philippine Time, a short time before moonrise. Just look at the east. For more info about the Total Lunar Eclipse this month visit the link below.
December night sky is pretty and rich with star clusters and made even prettier with Jupiter on the stage. The constellation Taurus the Bull contains the best known open cluster in the sky, the Pleiades or popularly known as the Seven Sister. Also in Taurus lingers the V-shaped star cluster Hyades which is clearly visible with the naked eye. This cluster contains the red bright star Aldebaran, the alpha star of Taurus. In the center of the constellation Perseus the Victorious Hero we can find the large Persei cluster. And between Perseus and Cassiopeia lies the famous Double Cluster. Moreover expect some beautiful pairings. The Moon, Saturn and Venus lies near each other on December 1-4, look east before sunrise, Venus is the light at its outstanding brightness. Look for Moon near Jupiter on December 13 and Moon near Pleiades on December 18.
Enjoy the night sky and Happy Christmas! :)
http://www.timeanddate.com/eclipse/lunar-eclipse-december-21-2010.html
Leonids 2010
Nov 17th
Mid-autumn sky is here and one of the most awaited event that’s going to peak late at night of November 17, 2010 until before dawn next day November 18, 2010 will once again visit us. At a zenith hourly rate of 20 meteors per hour, observers will have their share of excitement of what the Leonid has to offer.
The meteor shower will originate from the constellation Leo, thus the name Leonid. On the aforementioned date, Leo will rise at approximately 12:05AM but due to the waxing gibbous moon that will shine till after midnight, the Leonid will likely be at their best after the moon sets for the night.
The Leonid meteor shower comes from the debris of the Comet 55P/Tempel-Tuttle. Every year, the earth passes through the debris cloud left by the comet. As the sand-sized specks enter the earth’s atmosphere, it produces a spectacular show of “falling stars.”
(Click this link and enjoy. Leonid Animation)
Historically, the Leonids have produced some of the greatest meteor storms in history. An all-time high was recorded last 1833. Possibly 240,000 meteors were seen over a nine-hour time span at some locations. North America and east of the Rocky Mountains had briefly experienced a ’storm’ of approximately over 200,000 meteors per hour. This incredible activity may have been due to a direct collision between Comet 55P/Tempel-Tuttle and the large dust clouds created when the comet moved into the solar system in 1800. These storms sometimes recur in cycles of 33 to 34 years. Most years though the Lion whimpers rather than roars, producing a maximum of perhaps 10-15 meteors per hour.
So folks, with the brief information said, all we have to do is to hope for a clear sky and enjoy the Leonid.
Courtesy:
http://www.environmentalgraffiti.com/featured/where-watch-leonid-meteor-showers/17469
http://earthsky.org/astronomy-essentials/earthskys-meteor-shower-guide
Draconid Meteor Shower
Oct 7th
Draco, the dragon, is one of the largest constellations in the northern sky spanning about 180 degrees around the north celestial pole and Ursa Minor. Draco is not easily recognizable except for its distinctive asterism called the Lozenge which forms the head of the dragon. This is formed by the stars Etamin (γ Draconis), Rastaban (β Draconis), Grumium (ε Draconis), and ν Draconis. Etamin is the constellation’s brightest star and some may see it as one of the eyes of the dragon together with Rastaban. ν Draconis is the faintest of the four stars which is also well-known as a fine double star. On the Draco’s tail is the faint star Thuban (α Draconis) which was the ‘North Star’ around 3000 BC. It was nearest to the north celestial pole at that time, but because of the wobbling of Earth or the movement called precession, the position of the stars changed. Today, Polaris is considered as the ‘North Star’. In the center of Draco lies NGC 6543, a planetary nebula also called the Cat’s Eye Nebula.
Draco is the radiant of Draconid meteor shower, near the head of the dragon to be strict. Also called Giacobinids, it is known to produce a lot of meteors in an hour occasionally and it is best viewed in northern hemisphere. The meteor shower’s source is the periodic comet 21P/Giacobini-Zinner, named after its discoverers. Draconids produces slow-moving, yellow, but not particularly bright meteors in an irregular zenithal hourly rate. It is unpredictable and might give a wonderful show in the night sky. The 1933 Draconids is famous for it produced an average of 6000 meteors per hour. The 1946 Draconids also showed a very promising of thousands meteors per hour.
There is no assurance of a numerous display of meteors but this year is favorable for viewing Draconid meteor shower. On its peak around October 7, the moon’s phase is new giving the astronomers and sky enthusiasts a dark sky for observation. Draco peaks at nightfall so you don’t have to stay up late to wait for this worth-watching meteor shower.
Radiant of Draconids
Watch out for these slow-moving and yellow meteors! You can spot Draco in the north just after sunset, moving slowly around the north celestial pole.
http://earthsky.org/tonight/legendary-draconids-boom-or-bust
October Sky
Oct 5th
The noticeable asterism Great Square of Pegasus, the body of the winged horse, is high up in the night sky. The square is formed by the stars Markab (α Pegasi), Sheat (β Pegasi), Algenib (γ Pegasi), and Alpheratz (α Andromedae). The constellations Andromeda, Cassiopeia, and Perseus situate northeast of the square together with the closest large galaxy and the largest member of the Local Group of galaxies, Andromeda Galaxy or M31, which can be seen through binoculars. Another member of the Local Group of galaxies, Triangulum Galaxy or M33, lies near Andromeda. In Cassiopeia, an open cluster M52 can be seen as a faint hazy patch through binoculars. To the south of the square lie the Circlet of Pisces and Y-shaped Water Jar of Aquarius, the asterisms of zodiacal constellations Pisces and Aquarius. The summer triangle now lies in the western sky. Taurus, Auriga, and Orion, the constellations of the winter sky, linger in the eastern sky. Fomalhaut (α Piscis Austrini) and Archernar (α Eridani) shines in the southern sky. Jupiter is dominant this month and lies high in the sky surrounded by Pisces, Cetus, and Aquarius.
Draconid meteor shower, one of the least active meteor showers, will reach its peak on October 7 and 8. Meteors will radiate from the head of dragon, Draco. Witness the Draconids in the north as the darkness fall.
Orionid meteor shower will reach its peak around October 21, having an average of 20 meteors per hour. They will radiate from the Great Hunter Orion near Gemini. Orion will rise high late at night and the moon will be near full. Orionids will be best watched after moonset.
This month, catch a sight of Comet 103P/Hartley 2 a small comet with an orbital period of 6.5 years. On the first days of October it will sweep near Cassiopeia. On October 8, it will pass near the Double Star cluster NGC 869 in Perseus. On October 20, it will make its closest approach to Earth and will be located near Auriga. On October 28 it will make its closest approach to the Sun. We’ll have a better view of the small comet on the first half of the month when the moon light is not interfering in the darkness of the night sky. As the moon waxes through the month, it will completely affect night sky observation. On October 20 the moon is near full so the comet will be best observed after moonset but the amount of time for observation will be shorter as the Sun will soon rise.
- Path of Comet 103P/Hartley 2
New Moon: October 7, 2010
First Quarter Moon: October 15, 2010
Full Moon: October 23, 2010
Last Quarter Moon: October 30, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10173
September Sky
Sep 1st
The month of September would bring the long hours of daylight to a close, and a shift in the night sky would be seen. The Summer Triangle would step away from the spotlight and the autumn constellations would arrive. Soaring high in the night sky would be Pegasus, and surrounding Pegasus on three sides is a strange assortment cosmic objects named after mythical sea creatures. This month would mark the autumnal equinox, and in this period, the Sun would rise directly in the east and set directly in the west. The exact moment of equinox for this year’s September will occur by 11:09 am of September 23, 2010.
Highlights of the Month
- Close grouping of Spica, Mars and Venus, lying low on the western horizon after sunset at the start of the month (September 1). By September 11, they are joined by a thin crescent moon.
- Jupiter rising big and bright just south of the great square of Pegasus in the east, followed closely by Uranus, coming within one degree of each other. Jupiter reaches opposition on September 21 and presents a stunning disk that spans some 49 arc-seconds.
- The pre-dawn sky would give the best chance of observing Mercury this year at the latter half of the month as the ecliptic becomes well inclined to the horizon (September 14 to 29).
- Saturn passes behind the Sun on the 30th September but might just be glimpsed low in the west to the right of Venus during the first week or so.
- In the northern hemisphere, Capella in the constellation Auriga would twinkle brightly in the northeastern sky after midnight.
- Fomalhaut in the constellation Piscis Austrinus shines in the south. Fomalhaut, which is 25 light-years from Earth, made headlines in 2008 as one of the first stars to observed to have a planet that was directly imaged with telescopes.
- Moon phases this month:
Last Quarter: September 1
New Moon: September 8
First Quarter: September 15
Full Moon: September 23
- September 18 marks the first ever International Observe the Moon Night.
On Focus: Dark Energy
Aug 20th
Overview on Dark Energy
Dark Energy is one of the great mysteries of the universe. It was first discovered in 1998. And to this date, we’re not really sure what it is. All we know is that the universe is not behaving as we have expected it should.
Basically, the universe is expanding, but there will come a time that this expansion will slow down and stop. However this is not the case, instead of slowing down, it’s speeding up. So they predicted that there must be some kind of energy that’s pulling the universe to expand faster. But all energy must have a source, so exactly where does dark energy come from?
Although we still don’t have a full grasp on this concept, recently there has been a breakthrough in illuminating dark energy with gravitational lensing.
Use of Gravitational Lensing to view Dark Energy
Basically, gravitational lensing is the bending of light by massive objects. This phenomenon lead to many discoveries.
A group lead by Eric Jullo (Jet Propulsion Laboratory) and Priyamvada Natarajan (Yale) has used the light-bending power of the massive galaxy cluster Abell 1869 to their advantage. The gravity of the cluster causes galaxies behind it to be imaged multiple times into distorted shapes.
Distorted galaxies rim the edges of the gravitational lens Abell 1689, a galaxy cluster 2.2 billion light-years distant in Virgo. The purple overlay on this Hubble Space Telescope image shows the distribution of dark matter within the cluster.
They used their observations to model how dark energy altered the geometry of space along the route. To put it simply, the data was used to quantify the strength of the dark energy that causes the accelerating expansion of the universe.
“What I like about our new method is that it’s very visual,” said Jullo, “You can literally see gravitation and dark energy bend the images of the background galaxies into arcs.”
“We can now apply our technique to other gravitational lenses,” said co-author Priya Natarajan, a cosmologist at Yale University, New Haven, Conn. “We’re exploiting a beautiful phenomenon in nature to learn more about the role that dark energy plays in our universe.”
references:
http://hubblesite.org/newscenter/archive/releases/2010/26/full
http://www.skyandtelescope.com/news/101095989.html
August Sky
Aug 3rd
August Sky
The Summer Triangle formed by the bright star Vega of Lyra, Deneb of Cygnus, and Altair of Aquila is high up in the northern sky this month. Sagittarius the Archer and Scorpius the Scorpio lie in the southwest in front of the dense Milky Way. The Kite asterism of Bootes beside the Crown of Corona Borealis can be seen low in the west and the Square of Pegasus can be seen rising in the east leading the other stars. Aldebaran of Taurus, Betelgeuse of Orion, and the brightest star Sirius of Canis Major can also be seen rising in the east just before sunrise.
This month is also ideal for viewing meteor showers. Perseids, considered as the year’s top meteor shower peaks around August 12 after midnight. These bright meteors, at best, averaging 50 meteors per hour, can be seen radiating from the constellation of the Victorious Hero, Perseus in the northeast. The Hero will rise after midnight so most Perseid meteors can be seen only at that time. This year is also a great show for the Perseids because the moon will set early in the evening, leaving the whole night dark and ideal for observation.
Eclipse Circumstances
Jun 25th
Here are the circumstances of the Partial Lunar Eclipse on Saturday, June 26, 2010 computed for the Manila Observatory, QC.
All times are in Philippine Standard Time UTC+8h.
Site information
| Location: | Manila Observatory, QC |
| Latitude: | 14° 38′ 09.48″ N |
| Longitude: | 121° 04′ 41.16″ E |
| Elevation: | 103 metres |
| Time zone: | UTC+8h |
Visibility
The eclipse is partially visible from this location.
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