Over 4.6 billion years ago the Solar system was mostly gas and dust spiraling around a protostar that would eventually become the Sun. Only after more mass fell onto the protostar would enough heat and pressure build to ignite nuclear fusion in its core and generate light that would push away much of the dust that had not already coalesced into the planets. Now researchers at the National Radio Astronomy Observatory have found a system at that early stage just 450 light years away.
Called L1527 IRS the system appears to be just 300,000 years old, which means it did not even exist when the dinosaurs went extinct. If the protostar at its center though has consumed the gases around it especially fast though then the system could be even younger. Through careful measurements the researchers have managed to weigh the system and put the protostar at just one-fifth the Sun's mass, but it will likely match our star as it pulls from the accretion disk around it, which itself has enough mass to form seven Jupiter-sized planets.
A promising sign for this still developing solar system is the orbital speed of the gas and dust around the protostar as it matches what we see in our Solar System. This indicates that mass has a good chance of eventually coalescing into planets perhaps similar to our own and its neighbors.