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Hale-Bopp Comet of Goddard Space Flight Center (GSFC) from 1997
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Hale-Bopp: The Great Comet o
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| Title |
Hale-Bopp: The Great Comet of 1997 |
| Explanation |
Ten short years ago, Comet Hale-Bopp [ http://www.cometography.com/lcomets/1995o1.html ] rounded the Sun and offered a dazzling spectacle in planet Earth's night. This stunning view [ http://www.astropix.com/HTML/SHOWCASE/970401.HTM ], recorded shortly after the comet's perihelion passage on April 1, 1997, features the memorable tails [ http://www.ifa.hawaii.edu/~jewitt/tail.html ] of Hale-Bopp -- a whitish dust tail and blue ion tail. Here, the ion tail extends well over ten degrees across the northern sky, fading near the double star clusters [ http://antwrp.gsfc.nasa.gov/apod/ap060413.html ] in Perseus, while the head of the comet lies near Almach [ http://www.astro.uiuc.edu/~kaler/sow/almach.html ], a bright star in the constellation Andromeda. Do you remember Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970416.html ]? The photographer's sons do, pictured in the foreground at ages 12 and 15. In all, Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970328.html ] was reported as visible to the naked eye from roughly late May 1996 through September 1997. |
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Hale-Bopp on Schedule
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Hale-Bopp on Schedule |
| Explanation |
Late March and early April of 1996 marked a banner season for viewing the spectacular naked-eye comet Hyakutake [ http://antwrp.gsfc.nasa.gov/apod/lib/hyakutake.html ]. The spring of 1997 could well offer a similar cometary wonder, Comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap960723.html ]. Discovered last year [ http://newproducts.jpl.nasa.gov/comets/discovery.html ] while approaching the inner solar sytem Hale-Bopp has been eagerly watched [ http://www.eso.org/comet-hale-bopp/ ] for signs that it will indeed brighten spectacularly. So far, things look good! This recent image [ http://www.eso.org/comet-hale-bopp/phot-29-96.html ] of the comet was made on May 14 at the European Southern Observatory when the comet about 340 million miles from Earth. It is shown here using false colors to indicate relative brightness. Stars are visible through the expanding coma [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#coma ]. Recent reports are that its level of activity, the rate of dust and gas production from the solar heating of the icy nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap950821.html ] is as expected. An analysis of its orbit [ http://newproducts.jpl.nasa.gov/comets/ephemjpl1.html ] indicates that this comet will approach to within nearly 120 million miles of Earth on March 22, 1997. The orbital calculations also reveal that Hale-Bopp has visited the inner solar system before ... about 4200 years ago. |
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A Dust Jet From Hale-Bopp
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A Dust Jet From Hale-Bopp |
| Explanation |
Approaching the inner Solar System, comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap960725.html ]'s icy nucleus is heated by sunlight, accelerating its production of dust and gas. Shrouded in the resulting cloud, known as the coma, the cometary nucleus remains hidden from direct view. However, astronomers using a 2.2 meter telescope at the European Southern Observatory in May, were able to detect an enormous jet of dust [ http://www.eso.org/comet-hale-bopp/phot-29-96.html ] extending northward (up) from the nuclear region as seen in this false color image. Dust jets may arise [ http://www.aas.org/ApJ/v461n2/5610/sc0.html ] from vents on the surface of the nucleus. Early estimates of the size [ http://www.arcorp.com/Hale-Bopp.html ] of Hale-Bopp's nucleus have indicated that it could be as large as 40 kilometers (24 miles) in diameter -- several times larger than comet Halley [ http://antwrp.gsfc.nasa.gov/apod/ap950821.html ]'s. Hale-Bopp's copious dust production bodes well for it becoming a bright naked-eye comet in the spring of 1997 [ http://newproducts.jpl.nasa.gov/comets/index.html ]. |
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Comet Hale-Bopp Fades
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Comet Hale-Bopp Fades |
| Explanation |
Comet Hale-Bopp has faded in the past few weeks. For Hale-Bopp [ http://newproducts.jpl.nasa.gov/comet/ ], promised as the Great Comet of 1997, this was a bit of a disappointment -- but not entirely unexpected. Comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap960729.html ] continues to approach the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960916.html ] - making the comet itself brighten, but now the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap960819.html ] is moving away from it - making the comet appear to dim. Experts disagree on just how bright Hale-Bopp [ http://encke.jpl.nasa.gov/hale_bopp_info.html ] will become. Optimists hope it will eventually outshine Comet Hyakutake [ http://antwrp.gsfc.nasa.gov/apod/lib/hyakutake.html ], but some pessimists now expect no better than 3rd magnitude - hardly visible from well-lit cities [ http://antwrp.gsfc.nasa.gov/apod/ap960617.html ]. Comet Hale-Bopp [ http://www.eso.org/comet-hale-bopp/ ] still appears to be, however, a very large comet, and is sure to show much activity as it nears the Sun. The comet should reach peak brightness in March 1997. [ http://newproducts.jpl.nasa.gov/comets/ephemjpl3.html ] This image [ http://www.eso.org/comet-hale-bopp/comet-hale-bopp-summary-sep13-96-rw.html ] was taken on August 18th and shows gas shed from the nucleus of the comet. |
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A Hale-Bopp Triple Crown
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A Hale-Bopp Triple Crown |
| Explanation |
It was truly a busy sky. In one of the more spectacular photos yet submitted to Astronomy Picture of the Day [ http://www.phy.mtu.edu/apod/ ], Don Cooke of Lyme, New Hampshire [ http://www.state.nh.us/soiccnh/lyme.htm ] caught the Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ], Moon [ http://antwrp.gsfc.nasa.gov/apod/lib/moon.html ], Earth [ http://antwrp.gsfc.nasa.gov/apod/ap970130.html ], night sky [ http://antwrp.gsfc.nasa.gov/apod/ap970403.html ], Pleiades star cluster [ http://antwrp.gsfc.nasa.gov/apod/ap960903.html ], and Comet Hale-Bopp [ http://www.jpl.nasa.gov/comet/ ] all in one frame. The first leg of this "triple crown" exposure was of the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap960518.html ], taken at 6:55 pm on April 10th 1997. Through a dark filter, the Sun [ http://antwrp.gsfc.nasa.gov/apod/lib/sun.html ] appears as the bright dot on the lower right of the image. A second filtered exposure was then taken after the Sun had set, one hour and 40 minutes later - this time featuring the Moon [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-moon.html ]. The Moon appears as a crescent superimposed on an odd-shaped dark circle protruding into the left of the image. This shadow is actually a silhouette of a driveway reflector mounted on an aluminum rod used to block out the bright moon - so as to allow a third exposure, this time unfiltered, of the background night sky. And what a beautiful sky it is. Highlights include Comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970610.html ], on the right, and the Pleiades star cluster [ http://www.seds.org/billa/twn/m45x.html ], near the center. But what, you may wonder, is that bright light near the center of the picture? Don't worry if you can't guess: it's a porch light from a house across the river! |
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A Fisheye View of Comet Hale
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| Title |
A Fisheye View of Comet Hale-Bopp |
| Explanation |
Thousands of stars, several constellations, a planet and a comet all graced the western horizon over Ujue, Spain [ http://www.okspain.org/ ] just after sunset on April 4th, 1997. Because the picture was taken with a fisheye lens, much of the whole night sky [ http://antwrp.gsfc.nasa.gov/apod/lib/sky.html ] is visible. Comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970415.html ], with both tails blazing, appears right of center. The brightest [ http://www.astro.wisc.edu/~dolan/constellations/extra/brightest.html ] star is Sirius [ http://antwrp.gsfc.nasa.gov/apod/ap960902.html ] near the edge, well to the left of the constellation Orion [ http://astro.gmu.edu/constellation/ORI.html ]. The red star above the belt of Orion [ http://www.adler.uchicago.edu/ISE/ORION4.HTM ] is Betelgeuse [ http://antwrp.gsfc.nasa.gov/apod/ap970216.html ], while the red star near the center is Aldebaran [ http://antwrp.gsfc.nasa.gov/apod/ap970728.html ], just to the left of the bright Pleaides [ http://antwrp.gsfc.nasa.gov/apod/ap960903.html ] star cluster. Many other interesting astronomical objects are visible, including zodiacal light [ http://antwrp.gsfc.nasa.gov/apod/ap970826.html ], which is the diffuse triangular glow in the center. Even the planet Mercury [ http://www.seds.org/nineplanets/nineplanets/mercury.html ] appears just over the horizon. |
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Comet Hale-Bopp Over Indian
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Comet Hale-Bopp Over Indian Cove |
| Explanation |
Comet Hale-Bopp, the Great Comet of 1997 [ http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search?great+comet+1997 ], was quite a sight. No comets [ http://www.nineplanets.org/comets.html ] of comparable brightness have graced the skies of Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] since then. During this next month, however, even besides the fleeting Comet Bradfield [ http://antwrp.gsfc.nasa.gov/apod/ap040419.html ], "two" comets have a slight chance of rivaling Hale-Bopp [ http://www2.jpl.nasa.gov/comet/ ] and a good chance of putting on a memorable [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/comet.html ] sky show. Unfortunately, most of the show will be confined to sky gazers in Earth's southern hemisphere [ http://antwrp.gsfc.nasa.gov/apod/ap021222.html ]. Both comets are already visible [ http://encke.jpl.nasa.gov/RecentObs.html#02T7 ] to the unaided eye from there. The first, Comet C/2002 T7 (LINEAR) [ http://cometography.com/lcomets/2002t7.html ], should be at its best before dawn during the first weeks of May from the south. The second, Comet C/2001 Q4 (NEAT) [ http://cometography.com/lcomets/2001q4.html ], should be visible in early May from all over the Earth. Both comets [ http://www.space.com/spacewatch/comet_double_040319.html ] appear to be approaching [ http://skyandtelescope.com/observing/objects/comets/article_1037_1.asp ] the inner Solar System [ http://www.nineplanets.org/overview.html ] for the first time and so it is very hard to predict [ http://www.exploratorium.edu/exploring/space/kohoutek.html ] how bright each will become. In the above photograph [ http://www2.jpl.nasa.gov/comet/pach17.html ] taken 1997 April 6, Comet Hale-Bopp was imaged from the Indian Cove Campground in the Joshua Tree National Forest [ http://www.nps.gov/jotr/ ] in California [ http://www.state.ca.us/ ], USA [ http://www.cia.gov/cia/publications/factbook/geos/us.html ]. A flashlight [ http://www.geocities.com/~stuarts1031/flashlight.html ] was used to momentarily illuminate foreground rocks during this six minute exposure. |
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Hale-Bopp: A Continuing Tail
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Hale-Bopp: A Continuing Tail |
| Explanation |
Where is Hale-Bopp now? The Great Comet of 1997 [ http://www.jpl.nasa.gov/comet/ ], one of the largest and most active comets ever, is outbound [ http://antwrp.gsfc.nasa.gov/apod/ap970910.html ] about 400 million miles from the sun. Too faint for viewing without telescopes or binoculars, Hale-Bopp is presently positioned in the very southerly constellation of Pictor. This "negative" image [ http://www.eso.org/outreach/press-rel/pr-1998/phot-05-98.html ] (black stars against white sky) of Hale-Bopp is the result of a 1 hour time exposure using the 1-metre European Southern Observatory [ http://search.eso.org:8080/lasilla/generalinfo/html/aboutls.html ] Schmidt telescope on January 5. Clearly the comet still has a substantial tail [ http://antwrp.gsfc.nasa.gov/apod/ap971215.html ], blown by the solar wind [ http://antwrp.gsfc.nasa.gov/apod/ap970217.html ], that points generally away from the sunward direction. But look closely. A spiky "anti-tail" is also visible [ http://cfa-www.harvard.edu/iauc/06800/06812.html ] pointing toward the sun! It is likely that this anti-tail is composed of dust grains released from the comet nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap961210.html ] which are too large to be easily pushed by the solar wind. As Hale-Bopp recedes [ http://www.pha.jhu.edu/~weaver/hb_stis.html ] from the sun its activity will subside but astronomers are still uncertain as to how long its tails will last. After a swing through the outer solar system and the Oort cloud [ http://www.windows.umich.edu/comets/Oort_cloud.html ], Hale-Bopp will pass through the inner solar system again ... around the year 5400. |
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Hale-Bopp: The Crowd Pleaser
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| Title |
Hale-Bopp: The Crowd Pleaser Comet |
| Explanation |
In 1997, the bright comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap970320.html] may have become the most viewed comet in history [ http://medicine.wustl.edu/~kronkg/past_comets.html ] -- visible even to casual skywatchers in light polluted [ http://antwrp.gsfc.nasa.gov/apod/ap970830.html ] cities around [ http://antwrp.gsfc.nasa.gov/apod/ap970408.html ] the globe [ http://antwrp.gsfc.nasa.gov/apod/ap970515.html ]. In this picture, taken by photographer Joe Orman [ http://members.home.com/rmscott/orman_index.html ] on the evening of May 8, 1997, Hale-Bopp easily competes with near twilight skies and a shining, over-exposed, crescent moon above Mobile, Arizona, USA. Where is Hale-Bopp now [ http://www.jpl.nasa.gov/comet/ ]? Still visible [ http://encke.jpl.nasa.gov/whats_visible.html ] to telescopic observers in the Southern Hemisphere, the comet is outbound [ http://antwrp.gsfc.nasa.gov/apod/ap970910.html ], presently about 537 million miles from the Sun. (Jupiter orbits at about 480 million miles.) The long lead time provided by the early discovery of Hale-Bopp [ http://antwrp.gsfc.nasa.gov/apod/ap950820.html ] has allowed extensive observing campaigns [ http://www.eso.org/outreach/info-events/hale-bopp/ report-rw-hbitp98.html ] producing a bonanza of information [ http://www.jpl.nasa.gov/comet/news102.html ] about this primordial chunk of our Solar System [ http://stardust.jpl.nasa.gov/comets/comets.html ]. |
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The Dust and Ion Tails of Co
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| Title |
The Dust and Ion Tails of Comet Hale-Bopp |
| Explanation |
In 1997, Comet Hale-Bopp [ http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_ts?Bopp ]'s "intrinsic" brightness exceeded any comet since 1811 [ http://cometography.com/lcomets/1811f1.html ]. Since it peaked on the other side of the Earth's orbit, however, the comet "appeared" only brighter than any comet in two decades [ http://cometography.com/lcomets/1975v1.html ]. Visible above are the two tails [ http://antwrp.gsfc.nasa.gov/apod/ap960502.html ] shed by Comet Hale-Bopp [ http://www.jpl.nasa.gov/comet/ ]. The blue ion tail [ http://www-spof.gsfc.nasa.gov/istp/events/halebopp/disconnect/ ] is composed of ionized [ http://csep10.phys.utk.edu/astr162/lect/light/ionization.html ] gas molecules, of which carbon monoxide [ http://www.cpsc.gov/cpscpub/pubs/466.html ] particularly glows blue when reacquiring electrons [ http://www-spof.gsfc.nasa.gov/Education/welect.html ]. This tail [ http://antwrp.gsfc.nasa.gov/htmltest/gifcity/comet.html ] is created by the particles from the fast solar wind [ http://antwrp.gsfc.nasa.gov/apod/ap000318.html ] interacting with gas from the comet's head. The blue ion tail [ http://antwrp.gsfc.nasa.gov/apod/ap970514.html ] points directly away from the Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ]. The light colored dust tail [ http://antwrp.gsfc.nasa.gov/apod/ap970403.html ] is created by bits of grit that have come off the comet's nucleus [ http://antwrp.gsfc.nasa.gov/apod/ap000805.html ] and are being pushed away by the pressure of light [ http://antwrp.gsfc.nasa.gov/apod/ap000526.html ] from the Sun. This tail points "nearly" away from the Sun. The above photograph [ http://www.celestialimage.com/page101.html ] was taken in March 1997. |
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Comet Hale-Bopp Over the Sup
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Comet Hale-Bopp Over the Superstition Mountains |
| Explanation |
Four years ago, Comet Hale-Bopp [ http://galileo.ivv.nasa.gov/comet/ ] was discovered [ http://antwrp.gsfc.nasa.gov/apod/ap950820.html ] out near Jupiter [ http://www.seds.org/nineplanets/nineplanets/jupiter.html ] falling toward the inner Solar System [ http://spacelink.nasa.gov/Instructional.Materials/Curriculum.Support/Space.Science/Our.Solar.System/.index.html ]. Two years ago, it provided spectacular pictures [ http://antwrp.gsfc.nasa.gov/cgi-bin/cossc/apod_search?Hale-Bopp ] as it neared its closest approach to the Sun [ http://shutter.vet.ohio-state.edu/astronomy/faq/index.htm ]. Still today, spectacular pictures [ http://antwrp.gsfc.nasa.gov/apod/ap970723.html ] of the brightest comet of the 1990s are surfacing. Above, Comet Hale-Bopp was photographed in 1997 behind the Superstition Mountains [ http://www.goodnet.com/~rfidler/Page/Superstitions.htm ] in Arizona [ http://www.state.az.us/ ]. Clearly visible are the comets white dust tail [ http://antwrp.gsfc.nasa.gov/apod/ap960326.html ] that shines by reflected sunlight, and the blue ion tail [ http://antwrp.gsfc.nasa.gov/apod/ap970514.html ] that shines by glowing gas. Currently, there are several comets visible [ http://comets.amsmeteors.org/comets/current_comets.html ] from the proper location with a small telescope. A comet visible to the unaided eye [ http://encke.jpl.nasa.gov/bright_comet.html ] appears about once every five years. |
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