The habitable zones for both stars are the same width

The habitable zone for Star A is wider than the habitable zone for Star B

The habitable zones for both stars are at the same distance from their star

The habitable zone for Star A is at a smaller distance from its star than the habitable zone for Star B

The habitable zone for Star A is narrower than the habitable zone for Star B

The habitable zone for Star A is at a larger distance from its star than the habitable zone for Star B

It stabilises the Earth’s tilt

Eclipses are important for life on Earth

It produces tides on Earth

Interactions between the Moon and Earth strengthen the Earth’s magnetic field

Lava provided a liquid solvent necessary for the first life forms

Ejected material from volcanoes was launched into Earth’s orbit, eventually leading to the formation of our Moon

Outgassing contributed significantly to the development of the Earth’s atmosphere

The heat from volcanic activity played a significant role in making the Earth warm enough for liquid oceans

They infer the presence of plate tectonics, which are an important part of the temperature regulation cycle

They have very long main sequence lifetimes

Jovian planets are more likely to form around them

Terrestrial planets are more likely to form around them

They have low levels of stellar activity

Planets in the habitable zone are easier to detect via RV and transit methods

A 1.2 solar mass main sequence star with a temperature of 6,300 K

A 1.3 solar mass red giant with a temperature of 3,500 K

A 1.4 solar mass subgiant with a temperature of 4,700 K

A 0.9 solar mass red giant with a temperature of 3,200 K

A 0.8 solar mass main sequence star with a temperature of 4,700 K

They contribute to internal heating of the planet’s core through the greenhouse effect

They protect the surface from meteorites, which can burn up in the planet’s atmosphere

They regulate the planet’s temperature, moderating the difference between the dayside and nightside

They can provide sufficient pressure to ensure volatiles can exist in liquid states on the planetary surface

They produce a magnetic field, visible as aurorae, that shields the planet from harmful stellar radiation

Mars would spin faster

Mars would not have aurorae

Mars would have a thicker atmosphere

Mars would have plate tectonics

Mars would have a liquid magnetic core