ESA Hubble Photo Release | 2018 Jul 26
In summer 2018 the planets Mars and Saturn are, one after the other, in opposition to Earth. During this event the planets are relatively close to Earth, allowing astronomers to observe them in greater detail. Hubble took advantage of this preferred configuration and imaged both planets to continue its long-standing observation of the outer planets in the Solar System.
Since the NASA/ESA Hubble Space Telescope was launched, its goal has always been to study not only distant astronomical objects, but also the planets within our Solar System. Hubble’s high-resolution images of our planetary neighbours can only be surpassed by pictures taken from spacecraft that actually visit these bodies. However, Hubble has one advantage over space probes: it can look at these objects periodically and observe them over much longer periods than any passing probe could.
In the last months the planets Mars and Saturn have each been in opposition to Earth — Saturn on 27 June and Mars on 27 July. An opposition occurs when the Sun, Earth and an outer planet are lined up, with Earth sitting in between the Sun and the outer planet. During an opposition, a planet is fully lit by the Sun as seen from Earth, and it also marks the time when the planet is closest to Earth, allowing astronomers to see features on the planet’s surface in greater detail.
Saturn and Mars to Make Their Closest Approaches to Earth in 2018
NASA | STScI | HubbleSite | 2018 Jul 26