Mars
It can be sometimes, but Venus can be closer than Mercury ever can; Mercury is only the closest planet to Earth when Venus is on the opposite side of the Sun from Mercury and Earth, and maybe not even then (depending on exactly where Mars is).
Mercury is the closest planet to the sun, followed by Venus and the Earth
Mercury, Venus, Earth, Mars and Pluto are not gaseous. Pluto is sometimes not regarded as a planet. Jupiter, Saturn, Uranus and Neptune are gaseous, although the latter two may have a solid core of frozen gas.
Marnier 10 studied 2 planets, Venus and Mercury. It studied Venus on it's way to Mercury. Marnier 10 managed 3 fly-bys on Mercury before running out of maneuvering gas.
In our solar system, there are a total of 8 planets. Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune. Earth is the third one out from the sun.
The mariner spacecraft explored Mercury, Mars, and Venus. The first successful space probe and first spacecraft visit to a planet was Mariner 2.
It can be sometimes, but Venus can be closer than Mercury ever can; Mercury is only the closest planet to Earth when Venus is on the opposite side of the Sun from Mercury and Earth, and maybe not even then (depending on exactly where Mars is).
The closest planet to mercury is Venus.
The two closest planets to Venus are Mercury and Earth. Mercury is the closest planet to Venus, followed by Earth.
None of the Mariners actually landed on Venus. They were "fly-by" missions. Mariner 2 reached Venus in December 1962 and Mariner 5 in 1967. In 1973, Mariner 10 passed Venus and used the planet's gravity to alter its course and continued on to Mercury.
Basically the answer is "Venus". Mariner 2 flew past Venus. Pioneer 5 explored the space between Earth and Venus.
No, Venus is
Venus
Mercury and Earth are the two planets closest to Venus.
Venus is the second closest planet to the sun.
Mercury, Venus, Earth and Mars
venus