Easy Planet Mercury Trivia
Relative to the other planets how big is
Mercury?
A: It is the smallest.
How does Mercury’s orbit compare with the other
planets?
A: It is the innermost planet in the Solar
System.
How long is Its orbital period?
A: About 88 Earth days.
When viewed from earth, it appears to move
around its orbit in about how long?
A: 116 days.
Mercury has no known natural what?
A: Satellites.
What is Mercury named after?
A: The Roman deity Mercury, the messenger to the
gods.
Like Venus, Mercury orbits the Sun within
Earth's orbit as a what?
A: Inferior planet, so it can only be seen
visually in the morning or the evening sky.
Like Venus and the Moon, it displays the
complete range of what as it moves around its
orbit relative to Earth?/
A: Phases.
Mercury can appear as a bright star-like object
when viewed from where?/
A: Earth.
Mercury’s close proximity to the Sun often makes
it more difficult to see than what?
A: Venus.
Mercury is tidally or gravitationally locked
with what?
A: The Sun.
As seen relative to the fixed stars, it rotates
on its axis exactly three times for every what?
A: Two revolutions it makes around the Sun.
As seen from the Sun, in a frame of reference
that rotates with the orbital motion, it appears
to what?
A: Rotate only once every two Mercurian years.
An observer on Mercury would therefore see only
one day every what?
A: Two years.
Mercury's axis has the smallest “what” of any of
the Solar System's planets?
A: Tilt (about 1⁄30 degree).
What about its orbital eccentricity?
A: It is the largest of all known planets in the
Solar System.
At aphelion, Mercury is about 1.5 times as far
from the Sun as it is at what?
A: Perihelion.
Mercury's surface appears heavily cratered and
is similar in appearance to what?
A: The Moon.
This indicates that Mercury has been
geologically inactive for how long?
A: Billions of years.
Having almost no atmosphere to retain heat,
surface temperatures varies diurnally more than
what?
A: Any other planet in the Solar System.
Where does it’s temperature range from 100 K
(−173 °C; −280 °F) at night to 700 K (427 °C;
800 °F) during the day?
A: Across the equatorial regions.
The polar regions are constantly at what
temperature?
A: Below 180 K (−93 °C; −136 °F).
What two spacecraft have visited Mercury?
A: Mariner and MESSENGER.
When did MESSENGER, launch?
A: In 2004.
How many times did it orbit Mercury?
A: Over 4,000 times in four years.