Category Astronomy/Space

A new study suggests that distant “long-period” comets — which take more than 200 years to orbit the sun — are more common than previously thought. This illustration shows how the researchers used data from NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft to determine the nucleus sizes of several of these distant comets. They subtracted a model of how dust and gas behave in comets in order to obtain the core size. Credit: NASA/JPL-Caltech

1. The atmospheric superrotation at the upper clouds of Venus. While the superrotation is present in both day and night sides of Venus, it seems more uniform in the day (AKATSUKI-UVI image at 360 nm, right side), while in the night this seems to become more irregular and unpredictable (composite of Venus Express/VIRTIS images ar 3.8 μm, left). Credit: JAXA, ESA, J. Peralta (JAXA) and R. Hueso (UPV/EHU)
2. Examples of new types of cloud morphology discovered on the night side of Venus thanks to Venus Express (ESA) and the infrared telescope IRTF (NASA): stationary waves (Venus Express, up-left corner), “net” patterns (IRTF, up-right), mysterious filaments (Venus Express, down-left) and dynamical instabilities (Venus Express, down-right).
CREDIT: ESA, NASA, J. Peralta (JAXA) and R...

Slice through the celestial equator showing the radial component of the velocity field (in kilometres per second). Blue regions are falling towards us and red regions are flying away from us. Galaxies of the Sloan Digital Sky Survey main galaxy sample are overplotted. In the centre of the slice, the infalling dynamics of the Sloan Great Wall, one of the largest structure of the known universe, can be observed. Credit: University of Portsmouth