"Long before it's in the papers"
January 27, 2015


Comet seems to survive solar approach

Dec. 2, 2013
Courtesy of NASA
and World Science staff

Con­tin­u­ing a his­to­ry of sur­pris­ing be­hav­ior, part of Com­et ISON ap­peared on the oth­er side of the sun the eve­ning on Nov. 28—though the ob­ject van­ished from view dur­ing its clos­est ap­proach to the sun ear­li­er in the day, NASA sci­en­tists report.

The com­et in­i­tially seemed to dim and fiz­zle in sev­er­al ob­ser­va­to­ries, and lat­er could not be seen at all by NASA’s So­lar Dy­nam­ics Ob­serv­a­to­ry or by ground based so­lar ob­ser­va­to­ries. Many as­tro­no­mers thought it had dis­in­te­grat­ed al­to­geth­er.

But a streak of bright ma­te­ri­al stream­ing away from the sun ap­peared later in the Eu­ro­pe­an Space Agen­cy’s and NASA’s So­lar and He­lio­spheric Ob­serv­a­to­ry.

The ques­tion re­mains, scientists said, wheth­er it’s just de­bris from the com­et, or if part of the com­et’s nu­cle­us, or core, sur­vived. A pre­lim­i­nar­y anal­y­sis from sci­en­tists with NASA’s Com­et ISON Ob­serv­ing Cam­paign sug­gests that there is at least a small nu­cle­us in­tact.

Re­search­ers have watched Com­et ISON for the past year, es­pe­cially dur­ing its fi­nal ap­proach to the sun, and have al­ready seen the com­et bright­en and dim in un­ex­pected ways. Such bright­ness changes usu­ally oc­cur in re­sponse to ma­te­ri­al boil­ing off the com­et, they said. Dif­fer­ent ma­te­ri­al will do so at dif­fer­ent tem­per­a­tures, thus pro­vid­ing clues as to what the com­et is made of. The com­et is be­lieved to con­tain ma­te­ri­al as­sem­bled dur­ing the very forma­t­ion of the so­lar sys­tem some 4.5 bil­lion years ago.

Vi­deo here shows the com­et’s ap­proach to, and de­par­ture from, the so­lar neigh­bor­hood.

* * *

Send us a comment on this story, or send it to a friend

Sign up for

On Home Page         


  • St­ar found to have lit­tle plan­ets over twice as old as our own

  • “Kind­ness curricu­lum” may bo­ost suc­cess in pre­schoolers


  • Smart­er mice with a “hum­anized” gene?

  • Was black­mail essen­tial for marr­iage to evolve?

  • Plu­to has even cold­er “twin” of sim­ilar size, studies find

  • Could simple an­ger have taught people to coop­erate?


  • F­rog said to de­scribe its home through song

  • Even r­ats will lend a help­ing paw: study

  • D­rug may undo aging-assoc­iated brain changes in ani­mals

Continuing a history of surprising behavior, part of Comet ISON appeared on the other side of the sun the evening on Nov. 28—despite having vanished from view during its closest approach to the sun earlier in the day, NASA scientists say. The comet initially seemed to dim and fizzle in several observatories, and later could not be seen at all by NASA’s Solar Dynamics Observatory or by ground based solar observatories, astronomers reported. Many thought it had disintegrated altogether. But a streak of bright material streaming away from the sun appeared in the European Space Agency and NASA’s Solar and Heliospheric Observatory later in the evening, astronomers said. The question remains, they added, of whether it’s merely debris from the comet, or if some portion of the comet’s nucleus, or core, survived. But a preliminary analysis from scientists with NASA’s Comet ISON Observing Campaign suggests that there is at least a small nucleus intact. Researchers have watched Comet ISON for the past year, especially during its final approach to the sun, and have already seen the comet brighten and dim in unexpected ways. Such brightness changes usually occur in response to material boiling off the comet, they said. Different material will do so at different temperatures, thus providing clues as to what the comet is made of. The comet is believed to contain material assembled during the very formation of the solar system some 4.5 billion years ago. Video here shows the comet’s approach to, and departure from, the solar neighborhood.