Independence Day

2 July 2021

We’ve reached the mid-year, and the Fourth of July weekend for those of us in the States. In astronomy news, there are also several things to celebrate.

At the Edge

After the Event Horizon Telescope (EHT) made the first direct observation of a black hole in 2019, astronomers have been working towards making even better observations. This month there was a study of how the next-generation EHT could give us a look at the region of space right on the edge of the event horizon, which could help us understand the limits of general relativity. Another team looked at gravitational waves, and a new way we might detect them. If they are successful, their work could reveal the existence of planet-mass primordial black holes.

Head in the Clouds

Several studies on exoplanetary systems were published this month. One particular study looked at how an Oort cloud can form in a system. This work has the potential to change our understanding of how the solar system evolved. Another couple of studies looked at how life might appear on exoplanets. One argues that Neptune-like gas planets might harbor life in their atmosphere, while another argues that life might exist on rogue planets drifting through interstellar space. These sunless worlds could keep life warm and safe through geothermal energy. Finally, there was a study showing how a radio telescope on the far side of the Moon could detect potentially habitable exoplanets by observing their aurora.

Light and Shadow

Back in 2020, Betelgeuse dimmed significantly, leading some to speculate it might be ready to explode as a supernova. That didn’t happen, and now astronomers have learned the dimming was caused by dust obscuring its light. The cool thing about this study is that it reveals how complex molecules might scatter into space before a star explodes. In another study, astronomers looked at the dust created by a supernova to understand the core of the progenitor star. This will help us better understand Type Ia supernovae, which we use to measure cosmic distances.


New research on the evolution of galaxies shows how supermassive black holes affect star formation in galaxies and how galaxies grow. The first was an observation that galactic winds from these black holes arise early on, which tends to clear gas and dust from their galaxies. Another looked at how this galactic wind works to increase star production in satellite galaxies.

Pack Your Bags

Last, but not least, a more speculative study looked at the physics of interstellar travel, and how to calculate when to begin a journey to the stars. Do you take off as soon as you can, or do you wait until more advanced technology will get you there faster?

Many of you may be taking trips this Summer, and if you do I wish you a pleasant and safe journey. When you get back from your vacation, I’ll have more posts waiting for you. As always, if you like these articles, please share them with your friends.