Nasa is expected to make an announcement about ‘surprising activity’ on Jupiter’s moon, Europa, on Monday.

Many speculated that Nasa could finally be announcing evidence of life beyond Earth.

The space agency, however, has poured cold water over these claims, tweeting that the much anticipated announcement will not be related to aliens.

Jupiter’s sixth-closest moon Europa is one of the most interesting bodies in our solar system when it comes to the hunt for extra terrestrial life. Now Nasa has released a cryptic message saying ‘surprising’ evidence about the moon will be announced on Monday

Jupiter’s sixth-closest moon Europa lies 500 million miles from the sun and has an ocean lying beneath its surface which makes it one of the most likely places in the solar system for life to thrive.

The press briefing will be held at 14:00 ET (19:00 GMT) on Monday, and broadcast in a live video stream.

‘Astronomers will present results from a unique Europa observing campaign that resulted in surprising evidence of activity that may be related to the presence of a subsurface ocean on Europa,’ Nasa officials wrote.

Nasa categorically stated in a later tweet that the discovery, which is due to be revealed on Monday is ‘NOT aliens’

The images presented will have been taken by the Hubble space telescope.

Because Europa has the potential to have more liquid water than we have on Earth, some had speculated that the surprise reveal could be evidence for life.

The 1,900-mile-wide (3,100 km) moon harbors a huge ocean of liquid water beneath its icy shell.

Astronomers think this ocean is in contact with Europa’s rocky mantle, making all sorts of interesting chemical reactions a possibility.

Instead of direct evidence of life, however, experts have said it is more likely to be a step towards finding it.

The announcement could be related to faint plumes of water spotted on the moon back in 2012.  This graphic shows the location of water vapor detected over Europa’s south pole in December 2012

This is an artist’s concept of a plume of water vapour thought to be ejected off the frigid, icy surface of the Jovian moon Europa, about 500 million miles (800 million km) from the sun

The announcement could be related to faint plumes of water spotted on the moon back in 2012.

Hubble used a spectrograph to see normally invisible plumes of water vapour, shown in pictures as blue pixels above the moon.

‘By far the simplest explanation for this water vapour is that it erupted from plumes on the surface of Europa,’ lead author Lorenz Roth of Southwest Research Institute in San Antonio said at the time.

‘If those plumes are connected with the subsurface water ocean we are confident exists under Europa’s crust, then this means that future investigations can directly investigate the chemical makeup of Europa’s potentially habitable environment without drilling through layers of ice.

‘And that is tremendously exciting.’

Bill McKinnon, a planetary scientist at Washington University in St. Louis, told Business Insider the announcement is likely to be connected to these plumes.

‘A plume confirmation would be a great thing,’ McKinnon added, but ‘I have no insider knowledge.’

Hubble’s instruments were not designed to see any of Europa’s geology or study what elements are present in the plumes, so an announcement of this kind is unlikely.