Short answer: Japan’s MMX spacecraft is planned to launch on October 19, 2026 at 19:41 UTC (October 20 in Asia and Australia). It is a rocket launch, so there is nothing to see in your sky. Watch it online. The mission is worth following because it is the first attempt to land on a Mars moon and bring a piece of it home.

MMX Launch: Quick Answer

Quick facts for the MMX launch: date, rocket, sample size, Mars arrival and return to Earth.

What is MMX?

MMX stands for Martian Moons eXploration. It is a mission by JAXA, Japan’s space agency, with help from Europe, including the German and French space agencies. It will study Mars’s two small moons, Phobos and Deimos, and land on Phobos to collect a sample of at least 10 grams.

It will be the first mission to land on Phobos and the first to return a sample from the Mars system.

A small spacecraft with solar panels flying near a cratered moon, with Mars behind it.
Generated by SSE Team

Why visit a tiny moon?

Nobody knows where Phobos and Deimos came from. One idea says they are asteroids that Mars captured. The other says they formed from debris after a giant impact on Mars. A sample from Phobos could help settle that.

Phobos is only about 22 km (14 miles) across and circles Mars about three times a day. Its gravity is so weak that the spacecraft will not orbit it in the usual way. It will fly alongside it instead.

Phobos, a small cratered potato-shaped moon, with the large Stickney crater at the lower right.
Credit: NASA/JPL-Caltech/University of Arizona

Phobos is the larger and closer of the two moons. Deimos is smaller and farther out.

Mars with its two small moons, larger Phobos close in and smaller Deimos farther out.
Generated by SSE Team

Launch time in your city

The launch is planned for 19:41 UTC on October 19. Here is what that means where you live.

Table of the MMX launch time in UTC and eight cities, from New York to Sydney.
Table of the MMX launch time in UTC and eight cities, from New York to Sydney.

If your city is not listed, add or subtract your UTC offset from 19:41. Daylight saving time can shift this, so check your own clock.

How to follow it

You cannot watch this from your backyard. Follow JAXA’s official channels (they post on YouTube, X and Facebook) and check for a live broadcast closer to the date. We could not confirm whether the launch will be streamed, so look before you stay up.

If the launch is at 1:11 am where you are, the news coverage the next morning will cover it just as well.

Reality check

  • The date can slip. JAXA has reserved backup days until November 7, 2026, and the launch time may change during that period. Weather or a technical check can delay a launch by a day or more.
  • Launch is only the start. The spacecraft reaches Mars in the second half of 2027. The rover Idefix is planned to land on Phobos around the turn of 2028 to 2029. The sample is planned to reach Earth in 2031.
  • Dates are plans, not promises. Space missions move. We will update this page after launch.
  • You will not see Phobos yourself. It is far too small and faint for the naked eye.

What happens after launch

  1. Launch (October 2026): the H3 rocket lifts MMX from Tanegashima, Japan.
  2. Cruise (about one year): the spacecraft travels to Mars.
  3. Mars arrival (second half of 2027): it enters orbit and studies the moons.
  4. Landing on Phobos (planned around 2028 to 2029): the Idefix rover, a 25 kg wheeled rover built by German and French teams, is released about 40 m above the surface. Then the main spacecraft collects the sample.
  5. Return to Earth (planned 2031): the sample capsule comes home.

Timeline of the MMX mission

Timeline of the MMX mission: launch in October 2026, Mars arrival in 2027, Phobos landing around 2028 to 2029, sample back in 2031.

Keep going

Want more on what is up in the sky? See our Space Events Calendar. New to stargazing? Start with the Beginner’s Guide to Stargazing.

Sources