Space News & Blog Articles

What made Earth the planet that life chose? It's a question scientists have wrestled with for decades, and the answers are rarely simple. Distance from the Sun matters, liquid water matters and a magnetic field that deflects lethal radiation matters. But a new study published in the journal Terra Nova adds something unexpected to that list…. the slow, geological rise of the continents themselves, and a semi precious gemstone most people know from jewellery shops.

What are the little red dots? It's the question that has quietly obsessed astronomers since the James Webb Space Telescope first opened its eyes and started revealing the early universe in unprecedented detail. Hundreds of tiny, faint, reddish objects all sitting some 12 billion light years away, meaning we see them as they existed when the universe was barely a toddler. They showed up almost immediately and nobody could agree on what they were. Now, one maverick object hiding in a decade old data archive might finally have cracked it.

On a February morning in 2013, a rock the size of a house appeared without warning in the skies above Russia. The scary thing is that nobody saw it coming.

Decades of research shows that Earth was once entirely or almost entirely frozen. The episode is known as Snowball Earth, and though its occurrence is widely accepted, many of its details remain hypothetical. Snowball Earth took place in Earth's Cryogenian Period, which spanned from about 720–635 million years ago during the Neoproterozoic Era.

Ganymede, Jupiter's largest moon, is also the Solar System's largest satellite, even larger than the planet Mercury. It is also the only celestial body aside from Earth (and the gas giants) to have an intrinsic magnetic field. As if this didn't make the icy body interesting enough, scientists also predict that it has a massive interior ocean with more water than all of Earth's oceans combined. At present, the European Space Agency's (ESA) Jupiter Icy Moons Explorer (JUICE) is in transit to Ganymede to explore it for signs of habitability.

Life on Earth depends on organic chemicals—the elements carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur—often referred to as CHNOPS. These elements enable life and make up about 98% of all living matter. But they don't do it alone. Biochemical activity inside of cells also requires small amounts of metals. These metals enable critical biochemical reactions.

Welcome back to our ongoing series, A Brief-ish History of SETI, where we examine the ideas and milestones that have come to define the Search for Extraterrestrial Intelligence (SETI). In Part I, we looked at the purpose and motivations for this field of study, some of the earliest experiments, and how they reflected a growing sense of curiosity about the cosmos and our place in it. In Part II, we examined the first SETI survey (Project Ozma) and its enduring legacy.