According to current cosmological theories, the Milky Way started to form approximately 13.5 billion years ago, just a few hundred million years after the Big Bang. This began with globular clusters, which were made up of some of the oldest stars in the Universe, coming together to form a larger galaxy. Over time, the Milky Way cannibalized several smaller galaxies within its cosmic neighborhood, growing into the spiral galaxy we know today.
Many new stars formed as mergers added more clouds of dust and gas and caused them to undergo gravitational collapse. In fact, it is believed that our Sun was part of a cluster that formed 4.6 billion years ago and that its siblings have since been distributed across the galaxy. Luckily, an international team of astronomers recently used a novel method to locate one of the Sun’s long-lost “solar siblings“, which just happens to be an identical twin!
Continue reading “Astronomers Find One of the Sun’s Sibling Stars. Born From the Same Solar Nebula Billions of Years Ago”
They say there’s more than one way to skin an interstellar cat, and in astronomy there’s more than one way to find alien exoplanets orbiting a distant star. With the recent shut-down of NASA’s prolific Kepler mission and its windfall of discoveries, it’s time to look towards the future, and towards alternatives.
Continue reading “The Power of the Wobble: Finding Exoplanets in the Shifting of Starlight”
In the course of searching for extra-solar planets, some very interesting finds have been made. Some of them have even occurred within our own galactic neighborhood. Just two years ago, astronomers from the Red Dots and CARMENES campaigns announced the discovery of Proxima b, a rocky planet that orbits within the habitable zone of our nearest stellar neighbor – Proxima Centauri.
This rocky world, which may be habitable, remains the closest exoplanet ever discovered to our Solar System. A few days ago (on Nov. 14th), Red Dots and CARMENES announced another find: a rocky planet orbiting Barnard’s star, which is just 6 light years from Earth. This planet, Barnard’s Star b, is now the second closest exoplanet to our Solar System, and the closest planet to orbit a single star.
Continue reading “Super Earth Planet Found Around One of the Closest Stars to us. But it’s Probably a Terrible Place to Live”
When it comes to the search for extra-terrestrial life, scientists have a tendency to be a bit geocentric – i.e. they look for planets that resemble our own. This is understandable, seeing as how Earth is the only planet that we know of that supports life. As result, those searching for extra-terrestrial life have been looking for planets that are terrestrial (rocky) in nature, orbit within their stars habitable zones, and have enough water on their surfaces.
In the course of discovering several thousand exoplanets, scientists have found that many may in fact be “water worlds” (planets where up to 50% of their mass is water). This naturally raises some questions, like how much water is too much, and could too much land be a problem as well? To address these, a pair of researchers from the Harvard Smithsonian Center for Astrophysics (CfA) conducted a study to determine how the ratio between water and land masses can contribute to life.
Continue reading “Exoplanets Will Need Both Continents and Oceans to Form Complex Life”
Welcome back to the latest installment in our series on Exoplanet-hunting methods. Today we begin with the very difficult, but very promising method known as Direct Imaging.
In the past few decades, the number of planets discovered beyond our Solar System has grown by leaps and bounds. As of October 4th, 2018, a total of 3,869 exoplanets have been confirmed in 2,887 planetary systems, with 638 systems hosting multiple planets. Unfortunately, due to the limitations astronomers have been forced to contend with, the vast majority of these have been detected using indirect methods.
So far, only a handful of planets have been discovered by being imaged as they orbited their stars (aka. Direct Imaging). While challenging compared to indirect methods, this method is the most promising when it comes to characterizing the atmospheres of exoplanets. So far, 100 planets have been confirmed in 82 planetary systems using this method, and many more are expected to be found in the near future.
Continue reading “What is Direct Imaging?”
Finding potentially habitable planets beyond our Solar System is no easy task. While the number of confirmed extra-solar planets has grown by leaps and bounds in recent decades (3791 and counting!), the vast majority have been detected using indirect methods. This means that characterizing the atmospheres and surface conditions of these planets has been a matter of estimates and educated guesses.
Similarly, scientists look for conditions that are similar to what exists here on Earth, since Earth is the only planet we know of that supports life. But as many scientists have indicated, Earth’s conditions has changed dramatically over time. And in a recent study, a pair of researchers argue that a simpler form of photosynthetic life forms may predate those that relies on chlorophyll – which could have drastic implications in the hunt for habitable exoplanets.
Continue reading “To Find Evidence of Life on Exoplanets, Scientists Should Search for “Purple Earths””
One of the more interesting and rewarding aspects of astronomy and space exploration is seeing science fiction become science fact. While we are still many years away from colonizing the Solar System or reaching the nearest stars (if we ever do), there are still many rewarding discoveries being made that are fulfilling the fevered dreams of science fiction fans.
For instance, using the Dharma Planet Survey, an international team of scientists recently discovered a super-Earth orbiting a star just 16 light-years away. This super-Earth is not only the closest planet of its kind to the Solar System, it also happens to be located in the same star system as the fictional planet Vulcan from the Star Trek universe.
Continue reading “Astronomers find Planet Vulcan – 40 Eridani A – Right Where Star Trek Predicted it.”
In of August of 2016, astronomers from the European Southern Observatory (ESO) confirmed the existence of an Earth-like planet around Proxima Centauri – the closest star to our Solar System. In addition, they confirmed that this planet (Proxima b) orbited within its star’s habitable zone. Since that time, multiple studies have been conducted to determine if Proxima b could in fact be habitable.
Unfortunately, most of this research has not been very encouraging. For instance, many studies have indicated that Proxima b’s sun experiences too much flare activity for the planet to sustain an atmosphere and liquid water on its surface. However, in a new NASA-led study, a team of scientists has investigated various climate scenarios that indicate that Proxima b could still have enough water to support life.
Continue reading “The Closest Planet Ever Discovered Outside the Solar System Could be Habitable With a Dayside Ocean”
In recent decades, astronomers have discovered many planets that they believe are “Earth-like” in nature, meaning that they appear to be terrestrial (i.e. rocky) and orbit their stars at the right distance to support the existence of liquid water on their surfaces. Unfortunately, recent research has indicated that many of these planets may in fact be “water worlds“, where water makes up a significant proportion of the planet’s mass.
Continue reading “Europan Space Whales Anyone? Planets Covered by Deep Oceans Can Still Have Life on Them”
Over the past few decades, the number of extra-solar planets that have been detected and confirmed has grown exponentially. At present, the existence of 3,778 exoplanets have been confirmed in 2,818 planetary systems, with an additional 2,737 candidates awaiting confirmation. With this volume of planets available for study, the focus of exoplanet research has started to shift from detection towards characterization.
Continue reading “How the Next Generation of Ground-Based Super-Telescopes will Directly Observe Exoplanets”