Astronomers have been fascinated with globular clusters ever since they were first observed in 17th century. These spherical collections of stars are among the oldest known stellar systems in the Universe, dating back to the early Universe when galaxies were just beginning to grow and evolve. Such clusters orbit the centers of most galaxies, with over 150 known to belong to the Milky Way alone.
A huge asteroid wiped out the dinosaurs, but what danger do smaller ones pose?
You too can be an astrophysicist with your new telescope
Supermassive black holes can turn star formation on and off in a large galaxy
In the 1970s, astronomers discovered that a particularly large black hole (Sagittarius A*) existed at the center of our galaxy. In time, they came to understand that similar Supermassive Black Holes (SMBHs) existed in the center of most massive galaxies. The presence of these black holes was also what differentiated galaxies that had particularly luminous cores – aka. Active Galactic Nuclei (AGN) – from those that didn’t.
High Above Jupiter’s Clouds
Maybe Mars and Earth didn't form close to each other
In recent years, astronomers have been looking to refine our understanding of how the Solar System formed. On the one hand, you have the traditional Nebular Hypothesis which argues that the Sun, the planets, and all other objects in the Solar System formed from nebulous material billions of years ago. However, astronomers traditionally assumed that the planets formed in their current orbits, which has since come to be questioned.
How long can a rocky world withstand the blast from a red dwarf star
Red dwarf stars have become a major focal point for exoplanet studies lately, and for good reason. For starters, M-type (red dwarf) stars are the most common type in our Universe, accounting for 75% of stars in the Milky Way alone. In addition, in the past decade, numerous terrestrial (i.e rocky) exoplanets have been discovered orbiting red dwarf stars, and within their circumstellar habitable zones (“Goldilocks Zones”) to boot.
Flying chariots and exotic birds: how 17th century dreamers planned to reach the moon
The Genesis Project: using robotic gene factories to seed the galaxy with life
In the past decade, the rate at which extra-solar planets have been discovered and characterized has increased prodigiously. Because of this, the question of when we might explore these distant planets directly has repeatedly come up. In addition, the age-old question of what we might find once we get there – i.e. is humanity alone in the Universe or not? – has also come up with renewed vigor.
You don’t need to build a rocket to prove the Earth isn’t flat – here’s the simple science
Galactic panspermia: Interstellar dust could transport life from star to star
The theory of Panspermia states that life exists through the cosmos, and is distributed between planets, stars and even galaxies by asteroids, comets, meteors and planetoids. In this respect, life began on Earth about 4 billion years ago after microorganisms hitching a ride on space rocks landed on the surface. Over the years, considerable research has been devoted towards demonstrating that the various aspects of this theory work.
A guide to meteor showers – what to look out for and when
It has happened to most of us: walking home late at night under clear skies you catch a glimpse of something bright moving, often from the corner of your eye. You turn to see what it is but it’s gone without a trace. And chances are you will have seen a meteor ending its multi-billion year journey in a burst of light 100km up.
The internal ocean of Saturn’s moon Enceladus could be old enough to have evolved life, finds study
We recently bade farewell to the Cassini spacecraft, which after 13 years of faithfully orbiting Saturn and its moons was directed to plunge into the giant planet’s atmosphere. The reason for the “grand finale” was to guard against the possibility that Cassini might crash into one of Saturn’s moons – in particular Enceladus.
Dinosaurs could have avoided mass extinction if the killer asteroid had landed almost anywhere else
The decline of the dinosaurs, the rise of mammals and, ultimately, the origins of humans were even more unlikely than previously thought, according to new research. The huge asteroid collision that sparked this change in the Earth’s diversity was already a highly improbable roll of the celestial dice. But a new study suggests the mass extinction that followed it was only so severe because of where the asteroid struck.
Enceladus had an internal ocean for billions of years
When the Cassini mission arrived in the Saturn system in 2004, it discovered something rather unexpected in Enceladus’ southern hemisphere. From hundreds of fissures located in the polar region, plumes of water and organic molecules were spotted periodically spewing forth. This was the first indication that Saturn’s moon may have an interior ocean caused by hydrothermal activity near the core-mantle boundary.
Are red skies at night a shepherd’s delight? An astronomer’s view
Humans have always used simple observations of nature to try to understand our complex environment and even the wider cosmos. One such example is: “Red sky at night, shepherd’s delight” and “Red sky at morning, shepherd’s warning”. These sayings – which date back to the Bible (Matthew 16:2b–3) – suggest that a particularly red sunset means clear weather is coming and a particularly red sunrise means it’s going to be bad weather or possibly a stormy day.
What is space? The 300-year-old philosophical battle that is still raging today
Mountains. Whales. The distant stars. All these things exist in space, and so do we. Our bodies take up a certain amount of space. When we walk to work, we are moving through space. But what is space? Is it even an actual, physical entity? In 1717, a battle was waged over this question. Exactly 300 years later, it continues.
Our Universe is too vast for even the most imaginative sci-fi
As an astrophysicist, I am always struck by the fact that even the wildest science-fiction stories tend to be distinctly human in character. No matter how exotic the locale or how unusual the scientific concepts, most science fiction ends up being about quintessentially human (or human-like) interactions, problems, foibles and challenges.
To find aliens, we must think of life as we don’t know it
From blob-like jellyfish to rock-like lichens, our planet teems with such diversity of life that it is difficult to recognise some organisms as even being alive. That complexity hints at the challenge of searching for life as we don’t know it – the alien biology that might have taken hold on other planets, where conditions could be unlike anything we’ve seen before.
Cosmic alchemy: Colliding neutron stars show us how the universe creates gold
For thousands of years, humans have searched for a way to turn matter into gold. Ancient alchemists considered this precious metal to be the highest form of matter. As human knowledge advanced, the mystical aspects of alchemy gave way to the sciences we know today. And yet, with all our advances in science and technology, the origin story of gold remained unknown. Until now.