... Tonight's Sky . ... Observing . ... An artificial comet holds secrets to Earths life . ... Rosetta takes cometт??s temperature . ... But, using the sensor to collect infrared light emitted by the whole comet, scientists determined that its average surface temperature is about 94 Fahrenheit ( 70 Celsius). ... Only registered members of Astronomy.com are allowed to comment on this article. ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...