question João Pedro MS, Rio de Janeiro, RJ
illustrates Samuel Leme
edition Felipe van Deursen
It varies a lot, of course. Basically, there are four factors involved: composition of the atmosphere, illumination from nearby stars, particles suspended in the air, and reflection from soil components. So it’s possible to make estimates about what you would see if you could be on another planet and look up. But it’s better to take it easy. Until today, few probes have visited places outside Earth and the cameras they carried contained filters that favored the observation of other details, more interesting for scientists. So, there’s still a lot of room for speculation. And piracy.
MERCURY
The planet of night owls. Because it has no atmosphere, its sky is always black, with the right to stars – including a huge one, the Sun (after all, Mercury is the first in the solar system). Thus, the Mercury sky would be similar to what astronauts saw on the Moon.
VENUS
The atmosphere is very dense, to the point that the Sun does not even appear. Clouds of acids, such as sulfuric, make astronomers assume the sky is yellowish-white, but images from the Soviet Venera probes in the 1970s show an orange color.
MARS
The atmosphere rich in CO2, the reddish surface and the intense dust leave the predominant scarlet tone. At sunrise and sunset, the sky turns pink, and areas closest to the Sun turn blue. More or less the opposite of what happens on Earth.
JUPITER
Where the sky is clear, dirty yellow would dominate. But in the regions of storms, which are so common that they are reflected in the bands of the planet seen from space, substances such as ammonium hydrosulfide would spread orange, reddish and brown tones.
SATURN
On clear days, the rings would be breathtaking, as would the large moon Titan, which is deep orange. The problem is that almost always the clouds of ammonia and ammonium hydrosulfide would leave the sky like Jupiter’s, but more whitish.
URANUS
The large amount of methane gas would turn the Uranian sky a cyan hue. It is speculated, however, that the effect is not so bright in practice, since the Sun is very far away, making it difficult for light to reach the planet.
NEPTUNE
As in Uranus, blue is also predominant because of the existence of methane gas on the planet. The difference is that the even greater distance from the Sun would make the Neptunian sky darker for human eyes.
READ TOO:
– What is the origin of the names of the planets in the Solar System?
– How far can we see in the Universe?
– What does the Universe smell like?
– Where are we in the Universe?
OTHER PLANETS
HD 189733b, 63 light-years from Earth, would have cobalt-blue skies because its atmosphere is filled with a type of glass, which would scatter radiation.
HAT-P-11b (120 light-years) is illuminated by a red dwarf star and therefore would have red skies.
GJ 504b (57 light-years) has methane and is in a new and therefore hot system. Your sky would be pink.
CONSULTANCY Gustavo A. Lanfranchi, coordinator of the master’s degree in astrophysics and computational physics at the Cruzeiro do Sul University (Unicsul), Rafael Santucci, astronomer at Colégio Magno/Mágico de Oz, Sergio Pilling, coordinator of the master’s course in physics and astronomy at the University of Vale do Paraíba (Univap)