Sunrise over Brisbane.
A solar day is a measure of how long it takes the Earth to rotate from one noon to the next, and today's summer solstice also happens to be the longest solar day of the year.
The mass of the Earth is big enough that the gravitational force it creates can pull the hard shape of ice, rock and metal into a sphere.
NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA's Goddard Space Flight Center
Imagine the Earth pulling everything it is made up of, all of its mass, towards its centre. This happens evenly all over the Earth, causing it to take on a round shape.
Lasers being shone from the European Southern Observatory’s Very Large Telescope in Chile.
These lasers help remove the twinkles in the night sky and help astronomers see stars clearer on Earth than ever before.
How exactly do the stars twinkle in the night sky? As it turns out, the answer is full of hot air... and cold air.
A solar eclipse observed over Grand Canyon National Park in May 2012.
Grand Canyon National Park
More than 2,000 years ago, the Babylonians understood the cycle of eclipses. They also regarded them as signs that could foretell the death of a king.
A new detector could work out what's causing a heat flow from the Earth's interior. It may even solve the mystery of what powers the Earth's magnetic field.
NASA’s projection of the August 21 solar eclipse.
An astronomer explains how and why – and when – eclipses happen, what we can learn from them, and what they would look like if you were standing on the moon.
The Sun is currently middle-aged, having celebrated its 4,568,000,000th birthday at some point in the last million years.
In five or seven billion years time, the Sun's life will come to an end. And it will be really spectacular - if you're watching from far enough away.
Earth, shot from space, as it absorbs and reflects rays of light coming from the Sun - the same white-looking rays that give our sky its colour.
Some people think the sky is blue because of sunlight reflected off the ocean and back into the sky. But that's not the real reason.
A Boreal Shield lake in Algonquin Park, Ontario.
Canadians love to paddle on them and camp beside them, but our boreal lakes offer more than just peace and beauty. They could provide clues to how life on Earth began.
Jason Szenes / EPA
We need a positive vision for humanity, not tech-driven life on Mars.
The new map was created using data from rocks found in locations including Madagascar.
You would not recognise Earth if you saw it 500 million years ago - the lands, oceans, climate and life were all very different. Scientists now have a new map of the deep history of Earth.
The planet is more similar to Earth than any other – except when it comes to supporting life.
Between the Earth and the moon: An artist’s rendering of a refueling depot for deep-space exploration.
Sung Wha Kang (RISD)
To get us to Mars and beyond, a team of students from around the world has a plan involving lunar rovers mining ice and a space station between the Earth and the moon.
A scale model of one of the two LAGEOS satellites.
NASA's Goddard Space Flight Center
We know much about the true shape of our planet is thanks to two satellites that act as targets for lasers fired from Earth.
This illustration shows Cassini diving through geyser plumes on Saturn’s the ocean world
moon of Enceladus.
Earth is a relatively dry planet compared to some of the other ocean worlds in our Solar system. Life needs water so what about life on these other places?
Have we really discovered other “Earth-like” planets orbiting around other stars? Understanding what we do and do not know about exoplanets is the key to answering this question.
ESO/L. Calcada/N. Risinger/Reuters
Over the last 20 years, advances in the field of exoplanet discovery have excited the imaginations of scientists and enthusiasts alike. But we're in position to know yet whether a planet is habitable.
What’s north would become south.
Are we headed to a magnetic reversal and all the global disruption that would bring? Enter archaeomagnetism. A look at the archaeological record in southern Africa provides some clues.
Artist’s impression of an ice age.
The Earth's orbit has driven ice ages in the past but those days could be over.
Enjoy the full moon’s glow.
Full moons are good reason to look up – and the one on Nov. 14 is no exception. But here’s why you likely won’t see something shockingly different from other full moons you've observed over the years.
How to save the Earth from an asteroid strike.
Large asteroid hits on Earth have the potential to wipe out humanity so knowing how to detect and deflect them is vital. But we know very little about the interior make up of many asteroids.