2020 October 21 How big are the Planets?

Tutong – Mars, Saturn and Jupiter have reached opposition and shine extra bright in the evening sky in October 2020.

How large the planets appear in the sky, as seen through a telescope? This photograph of the planets taken last night shows the actual apparent size for comparison, measured in arcseconds (“).

The evening planets – Mars, Saturn and Jupiter on October 21, 2020 and their apparent angular size for comparison (Photographed by Hazarry Hj Ali Ahmad of PABD)

The following table shows the planets apparent size as seem from the ground telescopes. Notice that the size varies depending on the planets’ distance from the Earth because all the planets orbit the Sun on different elliptical paths.

ObjectMininum SizeMaximum Size
Sun1800″ 
Mercury4.5″13″
Venus9.7″66.0″
Moon1800″ 
Mars3.5″25.1″
Jupiter29.8″46.9″
Saturn (* with ring)14.5″ (33.8″)*20.1″ (46.9″)*
Uranus3.3″4.1″
Neptune2.2″2.4″

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