{"id":14538,"date":"2025-05-23T10:00:00","date_gmt":"2025-05-23T10:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=14538"},"modified":"2025-05-16T08:43:12","modified_gmt":"2025-05-16T08:43:12","slug":"cretaceous-australia-polar-dinosaurs-fossil-plant-evolution-may-2025","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/cretaceous-australia-polar-dinosaurs-fossil-plant-evolution-may-2025\/","title":{"rendered":"Comet, rocket, space junk or meteor? Here\u2019s how to tell your fireballs\u00a0apart"},"content":{"rendered":"\n\n\n
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\n A blaze of light streaks across the sky, but what is it?\n Wendy Miller\/Flickr<\/a>, CC BY-NC-ND<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n Michael J. I. Brown<\/a>, Monash University<\/a><\/em><\/span>\n\n

There\u2019s a blaze of light across the sky! A fireball is seen by thousands, and mobile phone and dashcam footage soon appears on social media. <\/p>\n\n

But what have people just seen? A mix of social media hashtags suggests confusion about what has streaked overhead<\/a>. Was it a Soviet Venus probe<\/a>? Was it one of Elon Musk\u2019s satellites or rockets? Was it a meteor? Was it a comet? <\/p>\n\n

While these objects have some similarities, there are crucial differences that can help us work out what just passed over our heads. <\/p>\n\n

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Shooting stars, meteors and comets<\/h2>\n\n

Shooting stars can often be seen on dark, clear nights in the countryside as brief flashes of light travelling across the sky. Usually, they are gone in just a second or two. <\/p>\n\n

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\n To capture a shooting star with this level of detail, your camera settings need to be just right, because they are very brief flashes of light.<\/span>\n Andrew Xu\/Flickr<\/a>, CC BY-NC-ND<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n

Shooting \u201cstars\u201d are not stars, of course. They are produced by dust and pebbles burning up high in the atmosphere, typically above 50km in altitude. Comets are often a source of this dust, and regular showers of shooting stars<\/a> happen when Earth travels through comets\u2019 orbits.<\/p>\n\n

Sometimes shooting stars burn with colours that reflect their composition \u2013 including iron, magnesium and calcium.<\/p>\n\n

Meteors and shooting stars are actually the same thing. But when people talk about meteors, they often mean bigger and brighter events \u2013 bolides. Bolides result from rocks and boulders plunging into Earth\u2019s atmosphere, resulting in bright flashes of light that can outshine all the stars and planets in the night sky.<\/p>\n\n

Bolides can reach the lower atmosphere and sometimes produce audible sonic booms. Occasionally pieces of the bolide \u2013 meteorites \u2013 even make it to Earth\u2019s surface.<\/p>\n\n

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