One of the key elements of the scientific process is that it demands repeatability. Observing something one time, especially something out of the ordinary or unexpected, and failing to observe it again, is usually cause for a casual dismissal of the event until it can be repeated.
And along with repeatability, there is a fairly conservative attitude toward explanations: simpler is better, familiar processes and objects are more likely than unobserved and uncharacterized hypotheses. There are always exceptions, and skeptics and scientists alike should remain open to possibilities outside what is expected and known. Journalists, though, have a different agenda, and headline writers... well, let's just say that the more unusual and provokative suggestion they can connect to the story, the better.
For years, a phenomenon known as 'Fast Radio Bursts' (FRBs) have been detected by only one source: Parkes Observatory in New South Wales, Australia. These bursts were infrequent, of unknown origin, and were never seen by telescopes elsewhere in the world. Some of the bursts, such as several observed in 2010, were clearly terrestrial. But others seem to have been received from celestial sources.
Interesting, but without more evidence, many researchers wondered if there was a technical problem at Parkes that caused it to report events that didn't exist.
This changes everything, from a scientific perspective. Now that there appears to be some confirmation that these events are not the result of a single telescope malfunctioning, the speculation as to what they represent has begun in earnest.
There are many hypotheses, most of them involving rather well-established objects, such as black holes, pulsars, and neutron stars. There is a body of research to confirm that these objects exist and astronomers have gotten very good at finding and defining them. A lot still remains to be known, though, and in that gap comes plenty of room for FRBs to operate. Working from existing research, with more data from FRBs coming available, astronomers will begin to test the hypotheses and eliminate those which are unlikely. This is the way science works.
Cue the aliens. I'm not wholly belittling this hypothesis, to be sure it could be non-terrestrial civilizations causing these events. It is possible. Even plausible, in a certain light, that we would be able to observe bursts of radio waves coming from civilizations. And you can bet that headline writers are already grasping at the possibility to sensationalize their work:
Mysterious fast radio bursts from outer space: Astronomers baffled, admit they could be alien in origin
Or this one:
Mysterious Radio Bursts From Space: Could it be Aliens?
Or this one (am I really linking to the Daily Mail?):
Are these mystery radio bursts messages from ALIENS? Freak frequency from outside the Milky Way baffles astronomers
Occam's Razor demands that, without enough evidence to pick which option is the mostly correct, we go with the one that demands the fewest assumptions, the one for which we have fewer complications. While we may not be able to differentiate between the hypotheses which include black holes and pulsars, we have no evidence that there are advanced alien civilizations, nor any non-terrestrial civilizations at all. Not yet, anyway. That doesn't stop headlines from adding the tempting possibility that aliens are behind the FRBs.
I get it. Headline writers have one job: grab the attention of potential readers and get them to click a link or open a newspaper (or so I hear, the latter is becoming less relevant every day). Including a mention of aliens is a lot more likely to get people to read an article than the much more honest and reflective of opinion verbiage, such as seen in this headline from Gizmodo:
No One Knows What's Causing These Mysterious Radio Bursts From Space
So when you see headlines which make grandiose claims involving aliens, miracle cures, or other verbiage which demands a great deal of evidence, and proof of which would be the biggest news story of the year, always take it with a grain of salt. Even when researchers make statements like
The nice things about this in the current stage is that we really don't know what these bursts are caused by. And so the sky's the limit in some respects
Please don't jump immediately to this: