Jeff Bezos tweeted a video of his lunar lander spewing green flames during a rocket engine test

Dave Mosher/Business Insider

Jeff Bezos unveiled the Blue Moon lunar lander in May.

• Jeff Bezos tweeted footage of the first engine test for Blue Origin's lunar lander.
• The engine is called BE-7, and is fuelled by hydrogen and oxygen.
• The flame burned bright green before turning entirely clear.
• Visit Business Insider's homepage for more stories.

Jeff Bezos showed off how work on his space exploration company Blue Origin's lunar lander is coming along, with an explosive video of a rocket engine test.

The Amazon CEO in May unveiled the "Blue Moon" lunar lander. At the same event Bezos, presented a squat yet flexible engine for the craft, named the BE-7, which burns hydrogen and oxygen as fuel.

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Bezos tweeted a video of the BE-7's first spectacular 35 second-long firing test at the NASA Marshall Space Flight Center on Thursday. The rocket's flame burns briefly green before turning completely clear, which The Verge reports is due to the ignition fluid used to start the combustion, which is quickly burned away.

You can watch the engine test here:

Bezos has said in the past that hydrogen and oxygen were selected to fuel the rocket, not only because they're effective, but also because he thinks Blue Moon will be able to refuel using ice which can be found in some of the moon's craters.