Life in the universe is a fascinating topic. The simplest question: Are we alone? It breeds so many deeper and more profound scientific questions, like “How many habitable planets are there?” “How likely is life to develop on any given planet?” and “How long can a civilization survive?” We can’t answer them definitively, but we can narrow it down. The Drake equation, shown above, was first developed by Frank Drake, the head of the Search for Extraterrestrial Intelligence (SETI), in 1961. He took the question of are we alone and made it quantifiable, in a probabilistic way. It lets us...
A direct consequence of Einstein’s theory of general relativity, and an observational way to prove it, is gravitational lensing. It requires a powerful gravitational source to work, such as a galaxy or cluster of galaxies. It works in a similar way to a lens of glass, where rays of light are bent toward a single source, increasing the brightness. In this case, instead of glass, the bending of the rays is due to the curvature of space. Light rays coming from the source would otherwise miss Earth, but instead are bent toward us when there is a massive object in front of it. It’s...
Looking at the universe in radio waves is a fascinating sight. For one, the radio sky is very weak; If you placed your cellphone on the Moon facing back at Earth, it would be brighter than all other radio sources in the entire sky by a factor of a million. But as with every other part of the electromagnetic spectrum, it has scientific value in studying the sky. Over the past decade, astronomers have been identifying several Fast Radio Bursts (FRB), short bursts of radio waves from different places in the universe that last for a few short seconds. These are...
I’ve covered a few ‘hidden galaxy’ stories lately, from the ultra high resolution see-through of Andromeda, to dark dust in front of M81 and M82. Now, hundreds of new hidden galaxies have been revealed by a team of astronomers who are looking straight through the Milky Way for the first time ever, shedding light on the structure of new galaxy clusters and the enigmatic pull of the ‘great attractor.’ The Earth is not stationary in space. It orbits the Sun, which in turn orbits the Milky Way galaxy, which then moves through the Universe as part of a galaxy cluster. ...
Black holes are the most extreme phenomena known in the universe. They are the absolute limit of what gravity and space-time can be twisted into. It’s no surprise that some of the most massive and advanced telescopes in the world are tasked with studying their properties and how they interact with their environment. But maybe there’s a way for you and I to see what a black hole can do, and all we need is a moderate 8 inch telescope and our eyes! Even though black holes generally give off tons of radiation, we need to observe them in the...
The only reason we can see black holes in the universe is because some of them swallow up gas and dust. This heats up material that is spinning rapidly around the black hole as it falls in (called an accretion disk), and produces massive jets of material due to conservation of angular momentum that can be seen across the universe. The energy released in the jets and the energy given off in the accretion disk are proportional to how much gas and dust is being consumed by the black hole. More matter = more food = more energy released. But...
Sometimes I love to say ‘I told you so,’ though in the world of science it’s more like ‘I gave you a high probability of this plausible scenario.’ A little while back a story broke about a star called KIC 8462852, with a strange ring of material surrounding it. One potential explanation was that an extraterrestrial civilization has constructed a giant ring to harvest it’s home star’s energy. Though this was one of a dozen possible explanations, it of course gathered the most steam among the general populace. In a statement today, officials from the Search for Extraterrestrial Intelligence (SETI) confirmed that...
Is this a giant hole in space? I show a picture similar to this as I ask this question to students and audiences that I host in my planetarium. Most people answer that it is a black hole, or dark matter, or dark energy, or something strange like that. But the amazing thing is that it is actually a thick cloud of dust that is opaque, letting no visible light from the distant stars pass through. The funny thing is that the cloud is transparent in infrared light, but in the visible spectrum it highlights something interesting about the universe:...
Honestly this could be the name of a new TV show, similar to ‘when buildings collapse,’ or ‘here’s what Kim Kardashian did today.’ I’ll take the colliding galaxies, simply because they can hold my attention longer. Galaxy collisions are some of the most massive and long term events in the universe. The result is the formation of billions of stars, the change in orbit of Billions more, and the complete restructuring of a galaxy. Since we see a snapshot of the Universe whenever we look at a single galaxy, we tend to see collisions happening at all stages of the...
Categorizing objects in the universe can be difficult. The fiasco with Pluto over the last decade is more than proof of that. We generally look to location and then to size as the two main methods for classifying the stuff that permeates the cosmos. Galaxies contain stars, which host orbiting planets, which host orbiting moons; While asteroids fly in between planets and icy comets are wander through the outskirts of star systems. But what about the in-between objects? Often we find strange things in strange places. There are moons in our solar system that are larger than planets. What would...
