Watch the king of the planets turn on its throne

Jupiter’s moon Io is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains up to 250 miles high. New NASA research suggests that tides flowing in a subsurface ocean of molten rock, or magma, could explain why Io’s volcanoes appear in the “wrong” place compared to models that predict how the moon’s interior is heated.

With astronomical twilight lasting all night around the Northern Hemisphere summer solstice for stargazers in the UK, what does the deep-sky observer do when the sky never gets truly dark? Fortunately, there are many beautiful double and multiple stars to seek out while most nebulae are off limits.

Venus has a close encounter with first magnitude star Regulus, constellation Leo’s luminary, in the dawn twilight on the mornings of 5 and 6 September.