Hidden Hazards: Unmasking Earth's Threat from Invisible Asteroids

SpaceTime with Stuart Gary

In this episode of SpaceTime, we delve into the intriguing world of near-Earth asteroids, the evolution of our universe, and the remarkable discovery of a rogue planet experiencing unprecedented growth.
Invisible Asteroids Near Venus: A Hidden Threat
Recent computer simulations published in the journal Astronomy and Astrophysics have raised alarms about a population of near-Earth asteroids that remain undetectable due to their proximity to Venus. These Venusian co-orbital asteroids, which share an orbital resonance with Venus, could pose a collision risk to Earth within a few thousand years. The study's lead author, Valerio Carumba, explains the challenges of observing these asteroids, as they are obscured by the Sun's glare. With a size of around 300 metres, these asteroids could create impact craters several kilometres wide, highlighting the need for dedicated space missions to monitor this potential threat.
The Universe's Evolution: New Insights from the Epoch of Reionization
Astronomers have made significant strides in understanding the universe's early days, revealing that it was warmer than previously thought before the first stars ignited. Research based on observations from the Murchison Wide Field Array in Western Australia indicates that the gas between galaxies was heated around 800 million years after the Big Bang, contradicting earlier theories of a cold universe. This heating, likely driven by early X-ray sources, set the stage for the epoch of reionization, which transformed the cosmos from opaque to transparent, allowing light to travel freely.
A Richie Planet's Remarkable Growth Spurt
In a groundbreaking discovery, astronomers have identified a rogue planet, catalogued as char 11 oh 7 minus 7626, that is not bound to any star and is growing at an astonishing rate of 6 billion tonnes of gas and dust per second. Located approximately 600 light years away in the constellation Chameleon, this planet challenges conventional notions of planetary stability. Observations reveal that its accretion rate fluctuates dramatically, highlighting the dynamic processes at play in the formation of rogue planets and blurring the lines between planets and stars.
www.spacetimewithstuartgary.com
✍️ Episode References
Astronomy and Astrophysics
https://www.aanda.org/
Astrophysical Journal Letters
https://iopscience.iop.org/journal/2041-8205
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Invisible Asteroids Near Venus: A Hidden Threat
The Universe's Evolution: New Insights from the Epoch of Reionization
A Richie Planet's Remarkable Growth Spurt
(00:00) The threat posed by invisible asteroids near Venus
(10:30) New findings on the universe's warm early phase
(19:00) Discovery of a rogue planet growing at record rates
(27:15) Science Robert: 2025 Nobel Prize announcements