Is there anybody out there?

UFOs (Unidentified Flying Objects) – now rebranded with a new moniker known as UAP (Unidentified Aerial Phenomenon) – have been spotted by American military pilots in 144 instances between 2004 to 2021. One was amusingly confirmed as a large deflating balloon, while the rest remain shrouded in mystery. The findings came in June 2021 from a nine-page “preliminary assessment” by the Office of the Director of National Intelligence, which coordinates the work of American intelligence agencies.

For decades, humans have been trying to find out if extraterrestrial (ET) life exists, or if they have made any sort of contact here on Earth.

Astronomers have also been looking up to the skies to probe for signs of ET life in the vast universe. With next-generation telescopes and space probes, scientists aim to peek into the darkness in search of exoplanets (planets that orbit other stars) that have all the conditions to possibly host life beyond our solar system. Armed with this knowledge, astrophysicists can then devise other experiments to probe for any evidence of life on other planets that might be dissimilar to those on Earth. After all, we need to keep an open mind for the sake of science – it could very well be life, as we don’t know it.

Hubble Space Telescope.

Marking its 30th anniversary in orbit last year, the iconic but elderly Hubble space telescope was revived in July 2021 by NASA technicians after being offline for over a month due to some technical glitches.

Ever since its launch, the telescope has been a gift that keeps on giving. Besides pioneering the search for exoplanets, it has also been used to figure out some of the earliest profiles of exoplanet atmospheres. Astronomers do so by using its wide-field camera to observe planets in near-infrared light, allowing them to decode the light and reveal clues to the chemical makeup of a planetary atmosphere.

Kepler Space Telescope.

Decommissioned in 2018, Kepler was instrumental in the discovery of thousands of exoplanets, and it remains credited with finding the most exoplanets of any mission so far – more than 2,600 of them. Scientists use Kepler to search for tiny dips in starlight as the exoplanets crossed the faces of their stars, known as the “transit” method.

The Transiting Exoplanet Survey Satellite (TESS), launched in 2018, picked up the baton and continued where Kepler left off, again conducting a grand survey of the sky. But TESS is definitely a far more advanced mission than that of Kepler’s – it’s designed to observe more than 85% of the sky, more than 300 times larger than what Kepler covered. Check out how the telescope decodes the universe to search for exoplanets in this video.

James Webb Space Telescope.

Slated for launch on December 22, the James Webb space telescope, also designed to be the successor of Hubble, will work hand-in-hand with TESS to uncover the mysteries of the universe.

Observing the universe in infrared light, Webb will scrutinise the overlapping observational areas made by TESS. This will enable astronomers to further explore and characterise the exoplanets detected around the stars in those regions. As a result,  highly refined measurements of planet masses, sizes, densities and atmospheric properties could be obtained, allowing astronomers to unveil the secrets of the universe one planet at a time.

Webb is highly anticipated to become the premier observatory of the decade, peering back in time to just after the Big Bang, giving us a more comprehensive understanding of the universe’s 13.7 billion-year-old history. Have a quick read on how Webb intends to achieve all that in this article!

From the ground up.

Collaborating with ground-based telescope teams is essential too. They can further confirm the observations made by space telescopes and probe deeper into the vast sea of data using powerful supercomputers.

The upcoming Square Kilometre Observatory (SKA), which was just recently approved for construction, will be able to detect extremely weak ET signals if they were to exist. For example, astrobiologists will use the SKA to search for amino acids, the building blocks of life, by identifying their spectral signatures at specific frequencies.

The SKA is so sensitive that it could detect airport-strength radar signals on planets many tens of light-years away. Perhaps one day you’d be able to tune in to Alien FM when you go on a road trip!

Are we alone in the universe?

With hundreds of exoplanets located in Goldilocks’ zones, otherwise known as habitable zones where conditions are neither too hot nor too cold to host life, it might make a little more sense to search for ET life at places familiar to us.

But with plenty of exciting science experiments on space exploration coming up, we might soon be able to answer this long-standing question that has tickled humanity’s curiosity bone for millennia: Are we alone in the universe?


Photo credits: Apostoli Rossella/Getty Images

By Mitchell Lim

Mitchell Lim is the latest addition to DUG’s science communication department. With a PhD in Chemical Engineering, Mitch is an expert in the fields of catalysis and ultrasonics. Full-time science geek, part-time fitness junkie, Mitch is living proof that brains and brawn are not mutually exclusive. His mission is to make science more accessible to you, while dreaming of having access to Martian land someday.