NASA s Hubble Space Telescope captured this image of Saturn July 4, 2020. Two of Saturn s icy moons are clearly visible in this exposure: Mimas at right and Enceladus at the bottom. This image is taken as part of the Outer Planets Atmospheres Legacy (OPAL) project. NASA, ESA, A. Simon (Goddard Space Flight Center), M.H. Wong (University of California, Berkeley), and the OPAL Team
There s a race happening in our solar system, but it has nothing to do with gravitational mechanics or velocity. Astronomers who study the gas giant planets of Saturn and Jupiter are in a close competition to see who can discover more moons. At this point, ringed Saturn is in the lead but exactly how many moons does Saturn have? And how does that compare to massive Jupiter s count?
Jupiter reaches equinox on
2 May 2021, a position where the geometric centre of the Sun’s disc appears to cross the equatorial plane of the planet.
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Compared to Earth, Jupiter’s axial tilt is quite small; 3.3˚ compared to our planet’s 23.4˚. For this reason, seasonal variations on Jupiter are relatively minor.
Of more significance from our perspective, the four Galilean moons Io, Europa, Ganymede and Callisto, have orbits only slightly inclined to Jupiter’s equatorial plane. A south-up telescopic view at 04:48 BST (03:48 UT) on 14 May will show the first of two of the month’s eclipses by Ganymede of Io; the second occurs on 29 May. Credit: Pete Lawrence
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Artist’s concept of the Juno spacecraft at Jupiter. Credit: NASA/JPL-Caltech
In a pair of mission extensions, NASA has cleared the way for more seismic observations on Mars with the robotic InSight lander and approved plans for the Juno spacecraft to alter its orbit and perform close flybys of Jupiter’s icy moon Europa, Ganymede, and the volcanic moon Io.
Christmas night astronomy: what to see in the night sky on 25 December
December 21, 2020 at 11:30 am
Aside from the turbulent year that was 2020, many people have discovered the joy of looking up at the night sky for the first time this year, and will have asked for a telescope this Christmas. Every year as the Sun sets at the end of Christmas Day, turkey-stuffed astronomy newcomers unpack their first telescope and head outside.
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Yet as new telescope owners stand there beneath the winter sky, their wacky Christmas jumpers hidden beneath thick coats and mighty Orion staring down at them, many may be disappointed – especially if the expectation was to see breathtaking views through their new telescope as good as the Hubble and Voyager images printed on its box.