A crewed mission to Mars could happen in 2029, SpaceX CEO Elon Musk hints.

A tweet on Monday comparing the moon landing to a future Mars landing attached a photo of the moon landing dated 1969, on top of an image of an envisioned Mars landing, labeled "20 --." The tweet, from Space_Hub, an account that posts about space and astronomy, read "What's your guess" and tagged Musk.

Two days after the tweet, Musk replied "2029."

Musk has long seen a visit to Mars as a goal. In 2016, he said he wanted to build a rocket capable of taking people to Mars and supporting a permanent city on the planet.

"It's something we can do in our lifetimes," he told an audience of 100,000 watchers at the International Astronautical Congress in Guadalajara, Mexico. "You could go."

But Musk's older predictions don't necessarily match up with his latest. In 2016, he told the Y Combinator, a startup accelerator, that getting a "meaningful number of people" on Mars was possible "in about 10 years, maybe sooner, maybe nine years."

Meanwhile, a joint Europe-Russia mission to Mars, called ExoMars, was suspended on Thursday due to the ongoing war in Ukraine. This rover mission, which is part of a two-part series, was set to launch in 2022.

The two-part mission was designed to investigate whether there is or ever was life on Mars.

"While recognising the impact on scientific exploration of space, ESA is fully aligned with the sanctions imposed on Russia by its Member States," the intergovernmental organization said in a release.

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