PIA18153: NASA's Hubble Sees Comet ISON Intact


NASA’s Hubble Sees Comet ISON Intact

Caption:

This image of the sunward plunging comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the sun warms it.

In this NASA Hubble Space Telescope image taken on October 9, 2013 the comet's solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments.

Moreover, the coma or head surrounding the comet's nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. What's more, a polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off.

This color composite image was assembled using two filters. The comet's coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars' orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on 26 December, at a distance of 39.9 million miles.

Cataloging Keywords:

Name Value Additional Values
Target C/2012 S1 (ISON)
System
Target Type Comet
Mission Hubble Space Telescope (HST)
Instrument Host Hubble Space Telescope
Host Type Space Telescope
Instrument
Detector
Extra Keywords Color, Dust
Acquisition Date
Release Date 2013-10-09
Date in Caption 2013-10-09
Image Credit NASA
Source photojournal.jpl.nasa.gov/catalog/PIA18153
Identifier PIA18153