Skip to main content

Earth is at its closest to the sun today: It’s perihelion day

Everyone knows the Earth goes around the sun, but something you might not know is that its orbit isn’t perfectly circular. Earth orbits in a slight ellipsis, so it isn’t always the same distance from the sun: sometimes it comes closer, and sometimes it’s further away. Today, Saturday, January 2, the Earth is at its closest point to the sun, in an event called the perihelion.

At its perihelion, the Earth will be just 91.5 million miles from the sun, compared to its further point (called the aphelion, which will happen on July 5 this year) when it is 94.5 million miles away. According to NASA, the distance between the sun and the Earth varies by around 3 million miles throughout the year, which is 13 times the distance between Earth and the moon.

Alas, that difference in distance isn’t enough to bring noticeable extra warmth, so if you’d been hoping for a warm day in the middle of winter in the northern hemisphere then you’re going to be disappointed. That’s because the seasons are caused by the tilt of our planet, which is set at a slight angle so some parts of the globe face the sun more than others at different times of the year. The tilt is different from the elliptical orbit, which is why we won’t be getting warmer weather even though we’re closer to the sun.

This year though we can expect to learn a whole lot more about our nearest star, with missions like the Parker Solar Probe which will be getting closer to the sun than any human-made object before to observe the sun’s corona. The probe will study the sun’s outer atmosphere to learn more about solar winds, which are streams of charged particles that are periodically released from the corona and which affect space weather.

There’s also the European Space Agency’s Solar Orbiter which has a camera on board to capture images of the sun directly, and which will take the closest-ever photos of the sun. Its aim is to shift in its orbit so eventually it will pass over the sun’s poles, which have never been observed before. Researchers believe that imaging the poles is essential for understanding the magnetic field of the sun.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble reveals glow of ‘ghostly’ light around our solar system
This artist's illustration shows the location and size of a hypothetical cloud of dust surrounding our solar system. Astronomers searched through 200,000 images and made tens of thousands of measurements from Hubble Space Telescope to discover a residual background glow in the sky.

Researchers using data from the Hubble Space Telescope have made a strange discovery: a "ghostly light" surrounding our solar system. When light from stars, planets, and even the glow of starlight scattered by dust is accounted for, there's still some "extra" light observed and astronomers are trying to work out where it's coming from.

The researchers looked at 200,000 Hubble images in a project called SKYSURF, looking for any excess of light beyond that coming from know sources. And they did find a consistent, faint glow that could suggest a previously unknown structure in our solar system. One suggestion is that there could be a sphere of dust surrounding the solar system, which reflects sunlight and causes the glow.

Read more
How to watch Orion make its closest approach to the moon on Monday
An artist's depiction of the Orion spacecraft flying close to the moon.

NASA's Orion spacecraft is heading through space and on its way to the moon and is set to make a close approach on Monday, November 21. If you want to follow along with Orion's journey you'll be able to tune into a live stream and see coverage of the spacecraft firing its engines and passing by the moon, using the moon's gravity to enter a distant retrograde orbit.

Artemis I Close Flyby of the Moon

Read more
NASA needs good weather for Artemis launch, here’s how it’s looking
NASA's SLS rocket on its way to the launchpad.

With two hurricanes in the last six weeks disrupting NASA’s plans for the maiden launch of its next-generation Space Launch System (SLS) rocket and Orion spacecraft, we’re happy to report that everything is looking good for the next launch attempt planned for early on Wednesday morning.

According to a forecast from the 45th Weather Squadron, which provides detailed assessments for air and space operations in the U.S., the conditions at the Kennedy Space Center in Florida are 90% favorable for the much-anticipated test flight of NASA’s new hardware.

Read more