Orbital

After much debate, it was decided that to be a planet in our solar system, an object must be in orbit around the Sun, have enough mass so that it has become round in shape due to its own gravity, and have cleared out its orbital path around the Sun.

Source: tatoeba (3955438)

Neptune was discovered because Uranus did not follow the orbital path predicted by astronomers. Astronomers assumed that the gravitational pull of another object was affecting the orbit of Uranus. This led them to look for, and find, Neptune.

Source: tatoeba (3957441)

Although others had floated the idea of orbital telescopes, Spitzer’s 1946 paper entitled “Astronomical advantages of an extra-terrestrial observatory” described in detail the scientific advantages of placing a telescope in space.

Source: tatoeba (8713622)

NASA’s Parker Solar Probe mission touched the Sun to provide us the first ever direct observations of the solar atmosphere, the corona, as well as traveling by Venus, where it gave scientists the first complete look at Venus’ orbital dust ring, detected a bright rim around the edge of the planet that may be nightglow, and discovered natural radio emission.

Source: tatoeba (10579498)