Mercury is tiny, barely bigger than the Moon. Its metallic core makes up 70% of the planet’s mass, vastly exceeding Earth’s 32% and Mars ’ 25%. It’s unlikely that the core actually formed like this.

New research presented at the Europlanet Science Congress 2025 in Helsinki suggests that Venus may be concealing some of the largest lava-carved tunnels ever discovered in the solar system. The ...

Something strange is moving through our solar system — and scientists are scrambling to figure out exactly what it is.

October's longer nights bring two transits of Titan across Saturn, while Io and Europa tango together across Jupiter three times. Mercury and Mars make a brief evening appearance, and Venus dominates ...

In the 17th century, astronomers Christiaan Huygens and Giovanni Cassini trained their telescopes on Saturn and uncovered a startling truth: the planet's luminous bands were not solid appendages, but ...

Check your daily horoscope for September 30, 2025, and plan your day accordingly. Get insights on love, career, finances, health, and relationships for all zodiac signs.