00:00We have observed the formation of giant planets in the disks around young stars before.
00:05But now, for the first time ever, we've discovered a planet-forming system that turns the clock back even further.
00:11Right to when the first specks of planet-forming material were created.
00:16Are we witnessing the dawn of a new solar system?
00:23Planets are born around young stars, which themselves form from giant clouds of gas and dust.
00:30These clouds collapse, and gravity from the nascent stars pulls in most of the material.
00:36The leftovers form a flat disk around the stars, a so-called protoplanetary disk.
00:41Tiny specks of dust and pockets of gas condense into solid material,
00:47and they collide and coalesce to form larger clumps, called planetesimals.
00:53Over millions of years, these grow further to finally become rocky planets, or the cause of gas giants.
01:00Our sun and its planets, including Earth, formed in exactly this way.
01:05If you want to know more about that, check out the video in the description.
01:08Now, a team of astronomers have observed a new planetary system, HOPs 315,
01:15that is causing a lot of excitement in the kind of nerdy circles I move in.
01:18It appears that, for the first time ever, we are witnessing the creation of the first specks of planet-forming
01:25material,
01:26and the moment a new planetary system is born.
01:30But how exactly do we know when the clock starts ticking on the formation of a new planetary system?
01:35Well, we look for the oldest solid materials.
01:40When a planetary disk is first formed, it is extremely hot.
01:44Generally, the first things that cool down enough to solidify are crystalline minerals,
01:50containing silicon monoxide.
01:53In our own solar system, these minerals are found trapped within ancient meteoroids.
01:57Many of them have not changed over time, and still hold the key crystalline minerals
02:03that geologists can use to date our solar system.
02:06And the best thing?
02:08We can analyse them right here on Earth.
02:13Like this meteorite here at the ESO supernova, a visitor from the asteroid belt between Mars
02:20and Jupiter that may have been orbiting our Sun since the beginning of the solar system.
02:25It was by radioactively dating rocks like this that we were able to date back the birth of
02:31our solar system to 4.6 billion years ago.
02:36Back to HOPS 315.
02:38What astronomers found in this planetary system is evidence for crystalline silicates just beginning
02:43to solidify.
02:44Specifically, they found silicon monoxide in its gaseous state and within crystalline minerals
02:50around the protostar.
02:52This suggests that they are witnessing the exact moment when it turns from gas into solid,
02:58and that we are seeing the very moment when the first specks of planet-forming material
03:04are created.
03:07As one of the involved scientists said, this process has never been observed in a protoplanetary
03:13disk before, or indeed anywhere outside our solar system, which makes this finding truly exciting.
03:20However, the initial observations gathered with the James Webb Space Telescope weren't sharp enough
03:26to figure out exactly where in the protoplanetary system the signal came from.
03:30So, the researchers turned to ALMA, in which ESO is a partner, to get data with better spatial resolution.
03:38With the ALMA observations, the team were able to determine that the signal they had picked up
03:43with JWST was indeed coming from the protoplanetary disk, tantalizingly from a region
03:49close to the star, at around the same orbit as the asteroid belt is in our own solar system.
03:55So, in HOPS 315, we are seeing this material at the same distance from the star as we find rocky
04:02planets and asteroids in our own solar system.
04:07Witnessing the dawn of a new planetary system is really cool in itself,
04:10but what makes HOPS 315 even more exciting is that it appears to look very similar to what
04:17our own solar system did 4.6 billion years ago. So, we can use this planetary system as a probe
04:24to find out what happened while Earth was forming and unravel our own cosmic history.
04:40Let's go.
04:41I can use that different points for these threeedeأن.
04:42Once we start doing this with your own solar system, please.
Comments