Nasa launched a basic one called Arecibo in 1974 but with better tech available today scientists want to update it.
The new spacebound note – dubbed the Beacon in the Galaxy – is the latest attempt to make contact with other lifeforms.
It will include our solar system’s position within the Milky Way relative to known clusters of stars so anyone who hears it can hunt Earth out.
Details about the Earth’s surface, drawings of humans and basic technical concepts for them to reach out to us will also be packed into it.
But a top researcher from Oxford University believes the move could be risky.
Dr Anders Sandberg told the Telegraph “it has such a high impact that you actually need to take it rather seriously”.
However, he thinks the chances of the message actually reaching extraterrestrials is quite low.
If it does, the broadcast will probably be more like “a postcard saying, ‘Wish you were here’,” he added.
There are quite a few communications out in space meant for aliens, which could also be a problem in itself.
“The poor aliens might already be getting various messages sent for all sorts of reasons,” Dr Sandberg said.
But the greatest issue is the “giggle factor” linked to all things alien and UFO.
“Many people just refuse to take anything related to it seriously – which is a shame, because this is important stuff,” he continued.
Dr Sandberg isn’t the first to worry about an invasion.
The late great Professor Stephen Hawking previously warned that these messages could pose a danger well.