TESS had a good look at the C/2018 N1 even before starting its science operations.

The Transiting Exoplanet Survey Satellite (TESS) of NASA started official operations on 25^th July 2018. Right before that, it underwent a final test to check its capabilities which presented a fascinating series of images to the researchers. It captured a moving comet for 17 hours which proves that this satellite can cover broad region of the sky and has the ability to capture prolonged set of stable periodic images. All these features are extremely crucial for locating transiting planets orbiting around nearby stars.

The comet observed during these tests is known as C/2018 N1. The Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) of NASA was behind this discovery which was announced on 29^th June 2018. It is present in the southern parts of constellation Piscis Austrinus and is at a distance of 48 million kilometers from the Earth. These images were captured in the last moments of the commissioning phase of the TESS’s mission. It only shows a minor part of its active field of view and the experts are still working on improving the performance of this satellite.

The movement of comet from right to left is clearly evident from these images while the gaseous tail of the comet extends to the top of the frame. These images had a lot more to show including stars, asteroids and stray light from Mars. Although Mars couldn’t be seen in these images, a faint arc of light from the red planet was observed in the dying moments of the released video. A possible explanation for this could be that these images were taken when Mars was at its closest distance to the Earth.

An infinite number of stars are also visible in these images who are shifting between black and white due to image processing. This shift of color clearly reveals the presence of variable stars. This means that the brightness of each of them may change for a different reason. According to the researchers, the variation in brightness is caused either by eclipsing binary neighbors, rapid rotation, or pulsation. Similarly, asteroids in the form of moving white dots are also there in abundance. You can get a good look at all of that in the video above.