Five Recent Comets
Since the beginning of mankind comets have amazed and mystified us. Over the past twenty years, our solar system system has witnessed some notable examples. These comets have been quite the spectacle for both astronomers and amateur stargazers alike. This five-page lens touches on some of the more important comets that have visited us over the past two decades.
Creative Commons photo courtesy Wikimedia/Sternwarte
Public domain animation courtesy Wikimedia/Anarchemitis
I can vividly remember observing the Hale Bopp Comet back in 1997. What an amazing thing it was to see. The comet was perhaps the most observed comet ever, having been visible to the naked eye for a period of 18 months. Coincidentally, it was also one of the brightest to have passed near our planet in recent years.
Creative Commons photo courtesy Wikimedia/Schnobby
The 1997 Hale-Bopp Comet was one of the brightest comets to reach the inner solar system in history.
Public domain photo courtesy Wikimedia/mkfairdpm
The Hale-Bopp Comet, also known as the Great Comet of 1997, was discovered separately by two amateur astronomers; Alan Hale, in New Mexico, and Thomas Bopp, located in Arizona, on July 23, 1995. The comet's extreme brightness was notable, as it was able to be seen by the naked eye for a record 18 months, more than twice as long as the previous record holder, the Great Comet of 1811.
During its visit, the Hale-Bopp Comet provided a massive amount of scientific information. NASA launched an unprecedented investigation of the comet, spearheaded by it's two most advanced observatories- the International Ultraviolet Explorer and the Hubble Space Telescope. Most astronomers thought that Hale-Bopp had a sizable nucleus up to 25 miles in diameter, while the average comet has a nucleus of about three or four miles in diameter or smaller. It is theorized that the asteroid, (or possibly comet), that struck Earth and led to the extinction of the dinosaurs around 65 million years ago, was roughly seven or eight miles in diameter.
Hale-Bopp was also notable because of it's properties. Scientists were shocked to discover that different types of ices that make up the comet's nucleus are somehow isolated from each other. The scientists also discovered that the comet had a third tail. While it is widely known that comets generally have 2 types of tails, dust and gas, this comet also had a sodium tail. This extremely long tail was found to contain neutral atoms. It was found to be located between the gas tail, which pointed away from the Sun, and the dust tail, which followed the comet's trajectory. Additionally, the Hale-Bopp Comet was also found to carry a huge amount of deuterium and argon. Argon had never before been discovered on any other comet.
Creative Commons photo courtesy Wikimedia/P. Salzgeber
Quick Comet Question
More Hale-Bopp Vids
Creative Commons photo courtesy Wikipedia/Sternwarte
In early March 1996, Comet Hyakutake first became visible to the naked eye. By the middle of March, the comet was still relatively faint, but as it neared its closest distance to Earth, it quickly became brighter, and its tail grew greatly in length. By the end of March, Hyakutake was one of the brightest night sky objects, taking on a greenish-blue color.
On the 25th of March the Hyakutake would be at its closest point to Earth. The comet was moving so quickly across the night sky that its motion could be seen against the stars in just a matter of minutes; it moved the diameter of a full moon about every half-hour. The head of the comet was a greenish hue, due to the diatomic carbon emissions.
Hyakutake was only at its peak brightness for a few days. Because of this, the comet it did not have time to capture the public's attention in the way that Comet Hale-Bopp would the next year. Many people Europe were unable to see in comet at its best due to poor weather across the area during that period.
Comet Hyakutake Video
In the above Hubble Space Telescope photo, the dark blotches show scars from Comet Shoemaker-Levy 9 fragments that struck the surface of Jupiter.
Public domain photo courtesy NASA/gov
Impact with Jupiter
The 1993 Discovery of Comet Shoemaker-Levy 9 is credited to astronomers Eugene and Carolyn Shoemaker and David Levy. Soon after its discovery, it was found to be a fragmented comet and possessed a decaying orbit around Planet Jupiter. SL 9 became fragmented in 1992 when it orbited close enough to be ripped apart by the Planets' gravitational forces.
The much anticipated impacts of the comet were witnessed between July 16, and July 22,1994. 21 impacts were observed over this period with the largest impact occurring on July 18, with a fragment causing a visible dark spot almost 9000 miles in diameter. This was the first time that astronomers had the good fortune to observe a collision of two space bodies.
The size of the original, unbroken comet vary, with some scientists estimating that the comet was somewhere between three and seven miles wide, with the largest impacting fragment somewhere around one mile in diameter.
S-L9 Impacts Jupiter
Public domain photo courtesy NASA/gov
Comet's Threat to Earth
The CST is on an orbit which puts it near to the Moon and the Earth. After its 1992 re-discovery, the comet's date of closest passage was miscalculated by 17 days. It was then noticed that, if its next visit (August 14, 2126) is also off by another 17 days, the comet would almost certainly strike the Moon or Earth. Given the size of Swift-Tuttle, this was quite alarming. This influenced astronomer Gary Kronk to look for ancient versions of the comet. He found the CST was probably seen by the Chinese in 69 BC and 188 AD. This information led scientists to recalculate its orbit, and deduce that Swift-Tuttle's orbit is very predictable, and that there is no impact threat over the next two milleniums. Astronomers feel that in the 2126 visit it will likely be a fantastic naked eye viewing opportunity, similar to the very bright Comet Hale-Bopp (1997).
This photo shows the head-on collision of the Tempel 1 Comet and the Deep Impact probe.
Public domain photo courtesy NASA/gov
Tempel 1 was first discovered on April 3, 1867 by astronomer Wilhelm Tempel, an while he was working in France. At that time, the comet's orbit was just under 5.7 years, and the Tempel 1 was also successfully viewed in 1873 and 1879. The comet did not become visible in 1884/1885 and it was believed to have broken up and disintegrated.
What astronomers in the late 1800s did not know is that Tempel1's orbit occasionally takes it close enough to Jupiter to affect it's orbit. It was not until 1967 when British astronomer Brian Marsden re-discovered the comet by recalculating the orbital path figuring in the influence of Jupiter's pull.
Tempel 1 is a fairly dim comet; its peak brightness so far has been too faint to be seen by the naked eye. Its size is roughly to be 8.5 by 2.4 miles, these calculations are based on measurements gathered by the Hubble Space Telescope.
Comet Tempel 1 was the target for NASA's Deep Impact space mission, where on July 4, 2005, a space probe was deliberately impacted on the comet's surface to gather scientific data. The next time Tempel 1 returned (in early 2011), it was once again studied closely from space, this time via the existing Stardust probe.
Tempel 1 Impact Video
Thoughts on This Hub, or the Comets? - Feel free to comment here. Thanks for visiting.
cayennemist on March 16, 2014:
Fun lens thanks
Doc_Holliday on January 23, 2014:
Looking forward to watching Rosetta harpoon C-G
blestman lm on June 02, 2013:
I used to star gaze when I was in high school. I had a friend who went on to become an astrophysicist. I still stop and gaze at the stars when the light pollution isn't too overwhelming
Cynthia Haltom from Diamondhead on May 11, 2013:
I like to star gaze. I have always been interested in science and have taught science for 33 years.
anonymous on April 16, 2013:
I've never seen any comets even though I look up a lot! It's probably because I don't go out much at night to look up at the sky. I know that a comet colliding with earth is a real threat but it doesn't concern me. I'm too worried about a leader having a bad dream and accidentally pushing a red button in his sleep. Hey! It could happen! (Not!) :)
dean_w on April 10, 2013:
very interesting. I didn't realize the number of comets that have been "in our neighborhood" in the past two decades.
TanoCalvenoa on April 04, 2013:
I was able to see Halley's Comet in 1986 (I was six years old), and one of the ones in the 90's, not sure which. I certainly remember what it looked like though.
Liz Mackay from United Kingdom on March 23, 2013:
Thanks for all the information on comets.
anonymous on March 23, 2013:
I really like this lens - thanks for building it.
StrongMay on March 15, 2013:
Tonight I am going to do my best to see Comet PanStarr, it only comes around every 100 thousand or 100 million years, I forget which (but you can find the info on space.com). It is not supposed to be so spectacular like some in the past, but it is something.
katrinakaifg on March 13, 2013:
norma-holt on February 01, 2013:
You certainly have done some great research and made an excellent report. Featured on Blessed by Skiesgreen 2013. Hugs
aliciamaggie54 on January 14, 2013:
I love this. I have been into comet gazing but your lens makes me want to now. I think it is amazing that scientist know when the next comet will come. Some space stuff is really interesting. I think it would be neat to be an astronaut. Thank you so much for sharing this information. A lot of it I had not even heard of. Thanks again. Have a great week:)
Judy Filarecki from SW Arizona and Northern New York on January 04, 2013:
Great lens. i especially enjoyed the videos and pictures.
anonymous on January 01, 2013:
Returning with fresh angel dust....what an amazing presentation and complimented nicely with the SciFi theme!
mrdata on December 26, 2012:
I love your valuable lens! Thanks a lot and Happy New Year!
getmoreinfo on October 23, 2012:
thanks for the information about the Five Comets of the Last 20 Years
Kumar P S on October 20, 2012:
Great lens ! Useful and informative. Thanks for sharing.
Kumar P S on October 20, 2012:
Great lens ! Useful and informative. Thanks for sharing.
BorisStewart on October 18, 2012:
Really interesting Lens, I like the comets!
hilman48 on October 14, 2012:
i see the hayle bob from field near the house , when I was 4 years old ,,,
Fantastic lens :)
Jogalog on October 14, 2012:
I'd love to see a comet but I think you need a good telescope to really appreciate them.
John Dyhouse from UK on October 13, 2012:
A very interesting lens, very informative.
scary-masks on October 05, 2012:
Fascinating subject - very thoroughly researched. Thanks.
mrkensworld on October 04, 2012:
Wow what a lens! Very nice.. The background is very striking when the lens is loading and the pics, info and videos are great. Quility lens here.. I shared this with all my social media sites. Very cool..
anonymous on October 01, 2012:
Interesting facts about comets thanks ......nice lens
spids1 on September 30, 2012:
great lens love this!
NewUsedCarsSacramento on September 28, 2012:
Anything related to space and outer world always excites me like anything. I enjoyed a lot reading your lens. Thanks for sharing such an wonderful lens.
MerlinFan on September 23, 2012:
Very interesting and informative lens, if not a little unsettling. However I did enjoy all the beautiful pictures and videos and actually learned quite a bit. Thank you for all the time you dedicated to this lens.
JoshK47 on September 22, 2012:
A truly fascinating read, indeed - thanks so much for sharing! Blessed by a space-loving SquidAngel!
Kay on September 21, 2012:
These are some amazing videos! Wonderful page. Blessed!
LabKittyDesign on September 21, 2012:
Unnerving to consider that the energy of the Shoemaker Levy impact was 6 MILLION megatons. And we just defunded NASA (yay!).
hijess on September 21, 2012:
Such beautiful pictures. Makes me remember that there's so much more out there than what's going on in our little heads.
resurrection7 on September 20, 2012:
comets remind me that the earth is young.....as they break up after about 10,000 years.....interesting lens though
Gloria Freeman from Alabama USA on September 20, 2012:
Hi I enjoyed reading your lens, thanks for sharing. Blessed and added to my lens Squid Angel flinnie.
Michey LM on September 20, 2012:
Very informative lens. Excellent pictures, I really like your presentation.
espada2005 lm on September 20, 2012:
very informative lens
SilmarwenLinwelin on September 20, 2012:
Fantastic, informative lens! I have featured this page on my space lens . Very well done!
webscan on September 19, 2012:
I am concerned about December 21st 2012. Any chances of a collision with one of them?
pheonix76 from WNY on September 19, 2012:
I love learning about comets, and lets not forget that they also bring us beautiful meteor showers! I loved watching comet Hale Bopp with my Dad -- it was a sight that I will never forget. Thanks for sharing, outstanding lens!
rudimanukwari on September 19, 2012:
Very interesting article. I am only now Comet Halley. thank
BestRatedStuff on September 19, 2012:
Tracy R Atkins on September 19, 2012:
anonymous on September 19, 2012:
Comets and Spacial Bodies have always Intrigued me as a Child and they still do as an Adult! ;D
ikepius on September 18, 2012:
Great lens. Strange that Hale and Bopp did not fight over who saw the comet first, who really discovered it. These days people fight over EVERYTHING. Nice work.
niralal on September 18, 2012:
VspaBotanicals on September 18, 2012:
Wow!!!!! I am completely blown away by this lens. Great job!
Babalucho86 on September 18, 2012:
Beautiful images and videos, beautiful lens!
faulco blogger85 on September 18, 2012:
My Dad loved comets
irubucom on September 18, 2012:
Interesting lens as I have been staring at the night sky for as long as I can remember.
Rosaquid on September 17, 2012:
I wonder if any new, spectacular comets are in store for naked-eye viewing soon? Thanks for this interesting lens.
SteveKaye on September 17, 2012:
Fascinating article on commets. Thank you for publishing it.
thememorybooksh1 on September 17, 2012:
Nice and informative lens..
anonymous on September 17, 2012:
I've never seen a comet
jarajelissa on September 17, 2012:
Joanie Ruppel from Keller, Texas on September 16, 2012:
A very educational lens - great job, enjoyed the videos.
RestlessKnights on September 16, 2012:
dahlia369 on September 16, 2012:
I just love this kind of images and the new theme goes perfectly with this exciting topic. Well done!! :)
anonymous on September 16, 2012:
What a thrill to see this beauty on the front page!
aquarian_insight on September 16, 2012:
Wow, an amazing lens - I thoroughly enjoyed it! Well done for all the work that went into it. *blessed*
Bill from Gold Coast, Australia on September 16, 2012:
I remember seeing Haleys comet in the 1980s, but I do nor remember seeing any of these ones! Great job and love the new theme!
sherioz on September 15, 2012:
What a beautiful and well done lens. Blessed.
anonymous on September 13, 2012:
An excellent and well written presentation of the five comets of the last 20 years and made even more spectacular with the new Sci-Fi theme, excellent and blessed!
blessedmomto7 on September 13, 2012:
Great resource, thanks. I'll have to share this with my kids when we study space.
Mary Norton from Ontario, Canada on September 12, 2012:
Your pictures and info are superb.
Shannon from Florida on September 12, 2012:
WinWriter on September 12, 2012:
I learned a lot on your lens. Well researched with great pictures and videos. I also liked the animation of the comet path. *Blessed *
Margaret Schindel from Massachusetts on September 12, 2012:
Wow, what a fascinating lens! Thanks so much for sharing. Blessed!
Shadrosky on August 23, 2012:
Very original lens topic! Well done!
MatijaB LM on August 17, 2012:
I love you lens - well done.
JamesDWilson on July 30, 2012:
Good lens, very informative and well written, thanks!
Liz Mackay from United Kingdom on July 22, 2012:
I lay on the frosty ground and tried to find Hale Bopp with binoculars but unfortunately didn't succeed. I guess I needed someone on hand like you to show me. I enjoyed the lens.
anonymous on July 21, 2012:
Love your information; you did a wonderful job on this lens. My dad was a sky-watcher, so I was raised looking for anything unusual. I remember all of us out on the back patio in the cold, stretched out in lawn lounge chairs all bundled up and watching falling stars.
Onemargaret LM on July 16, 2012:
Very interesting! Nice lens!
Brandi from Maryland on July 02, 2012:
Comets are fascinating...great lens! :)
Fcuk Hub on April 17, 2012:
Wow! you really know what you writing about: Great lens :)
theholidayplace on April 15, 2012:
Amaxing images and great info, great lens
KReneeC on April 04, 2012:
What a fascinating lens!
RecycleRRR on March 29, 2012:
MarkHansen on March 07, 2012:
Haley was the first planet I have seen
waldenthreenet on November 30, 2011:
Important topic. Any utility of a Commet someday ?
goo2eyes lm on October 18, 2011:
what if a big comet hits the earth? would it be zapped with laser guns? comet falling into the ocean will cause tsunamis.
peppervel on October 07, 2011:
Have been interested in comets, stars... anything in the universe and beyond since school days during which there were no internet... so spent hours in library flipping thru pages and pages of all these amazing stuff. now with a click ... I can admire these. Thanks for sharing those amazing beautiful pics and informations
elyria on October 02, 2011:
I am fascinated with comets and have seen several already. Once, back in college, I drove 8 hours just to see a passing comet in a huge telescope - it was so worth it!
adamfrench on October 02, 2011:
great lens, good information
SirAwesome on September 28, 2011:
Good information and an awesome lense! Keep up the great work!
ThomasJ4 LM on September 20, 2011:
I have always been fascinated by the solar system; great work!
trainstorm on September 19, 2011:
Nice reminder. I must stock up my cellar!!
bolsen19 on August 26, 2011:
A great, well researched lens.
dilipsvarma on August 20, 2011:
anonymous on July 19, 2011:
love it; the fact that the Earth is so big and the space is even bigger is a real amazing thing
sujaysen on June 14, 2011:
Comets are interesting as well as scary to me.
Blackspaniel1 on April 28, 2011:
The comets are interesting visitors
garyrh1 on March 27, 2011:
Not specifically about Hale-Bopp, but I love looking at the sky, stars, and all the other things in space.
jvsper63 on March 26, 2011:
Very enjoyable pretty lens..love comet's
MarianaFargasch on March 03, 2011:
I love comets I love anything that happens in the sky! Great lens!
Philippians468 on February 02, 2011:
comets always take my breath away! great lens! cheers
SandyPeaks on February 01, 2011:
@TheMonsterToySh1: I'll second that!
SandyPeaks on February 01, 2011:
Froze myself over several nights back in 1997 trying to film this!
TheMonsterToySh1 on January 01, 2011:
Great lens, I love anything about space, shame that so many people are wrapped up in their lives that they don't even consider how vast the universe is!!