Comparative Planetology and Observing Earth’s Neighbors

This planet is a small, incredibly hot world with a weaker version of Earth's magnetic field throughout the entire planet.

This planet has a sweltering climate. It is hotter than Mercury, despite being farther from the Sun.

The process by which atmospheric gases raise the temperature by absorbing outward-flowing heat.

This planet is too chilly for life to exist

It has many craters like the Moon, but it also has a molten iron core that creates a magnetic field, just like Earth.

This planet is considered as Earth’s evil twin.

This planet is the miniature Earth that dried up and cooled.

A bright planet appearing in the east before dawn.

A bright planet appearing in the west after sunset.

It is the angular separation between a planet and the Sun, as visible from Earth.

These happen when a planet is at its farthest possible distance from the Sun during a specific apparition.

A period of time when the planet is visible from Earth on successive nights.

It occurs when a planet is on the opposite side of Earth from the Sun.

It occurs when two solar system objects are near each other in the sky, such as when the Moon passes near Venus as we see them.

The position of a star measured in the east–west direction.

The position of a star measured in the north-south direction.

A circle in the sky that represents the path of the Sun through the constellations.

Measure degrees north and south or east and west with respect to the ecliptic.

It orbits outside the orbit of Earth

It orbits inside the orbit of Earth.

Glimpse out of the corner of your eye.

The dividing line between the bright and dark parts of Venus.

The pale glow on the dark part of Venus.

When a planet passes right in front of the Sun and looks like a tiny black disk against the bright solar surface.

A large dark area on Mars extending northward from the equator.

It maps and identifies the bright and dark regions of Mars that are visible using a tiny telescope. It provides more information than the typical observer ever sees, serves as a useful guide, and tests your observational abilities.

The steadiness of the atmosphere above the telescope.

The freedom from clouds and haze.

The freedom from interfering artificial light, moonlight, or sunlight.

Mercury is easiest to observe when it is at _____ and appears in the early morning twilight.

At its greatest elongation, Mercury appears to be only ____ arc seconds in size.