CNN  — 

In a first, viewers on Earth got a chance to see Mars nearly in real time.

The European Space Agency streamed on YouTube historic live images directly from the red planet.

The images, shared on YouTube, ESA’s Twitter account and with the hashtag #MarsLIVE, showed the planet in a way it has never been seen before, ESA said.

The event celebrated the 20th anniversary of the launch of the agency’s Mars Express orbiter — a mission to take three-dimensional images of the planet’s surface to see it in more complete detail.

“Normally, we see images from Mars and know that they were taken days before,” said James Godfrey, spacecraft operations manager at ESA’s mission control center in Darmstadt, Germany, in a statement. “I’m excited to see Mars as it is now — as close to a martian ‘now’ as we can possibly get!”

But haven’t we seen images of Mars before? Yes, but not live, the ESA said.

Often data and observations of the red planet are taken when a spacecraft is not in direct contact with Earth, so the images are stored until they can be sent back, ESA said.

Depending on where Mars and Earth are in their orbits around the sun, the messages that journey through space can take anywhere from 3 to 22 minutes.

The ESA had estimated it would take about 17 minutes for the light needed to form the images to travel directly from Mars to Earth and then another minute to get through the wires and servers on the ground to get the live stream started, the agency said.

ESA shared images it deemed as close to live as physically possible during a June 2 event. The images were pinged back to Earth with about a 17-minute delay, or as much time as it takes for the information to travel between Mars and Earth.

“Note, we’ve never tried anything like this before, so exact travel times for signals on the ground remain a little uncertain,” the agency said in a statement prior to the event.

No stars were visible in the background of the images because Mars is quite bright, noted Colin Wilson, a project scientist at ESA.