Birth in the cosmos begins with chaos and gravity, yet the earliest chapters of a star’s life are anything but quiet. Young stars are surrounded by a flurry of activity as they accumulate mass from their natal clouds while simultaneously launching narrow, collimated jets of gas into space. These jets travel at incredible speeds, carving channels through the surrounding gas and dust. Where the jet slams into the dense material that blankets the newborn star, the impact heats and excites the gas, producing bright, knotty features known as Herbig-Haro objects. Each of these glowing patches marks a moment in the star’s adolescent era, tracing how material is redirected and dispersed as the young star grows. The features flicker into view and fade away on timescales of roughly a thousand years, offering astronomers a fleeting, dynamic record of star formation in action. Collectively, they reveal a back-and-forth process: gravity pulls matter inward to form the star, while powerful outflows push material outward, shaping the larger stellar nursery and influencing whether planets can eventually take shape in the surrounding disk.
To understand these processes in detail, astronomers observe across the electromagnetic spectrum. Infrared light pierces dust that would otherwise hide the jets, while radio waves reveal the cold gas swirling around the newborn star. A specialized instrument, the Atacama Large Millimeter/submillimeter Array (ALMA), provides unprecedented resolution for these distant features. A recent high-resolution image captured by ALMA shows a striking pair of jets emerging from a young protostar. The jet on the left, tinted pink and purple in the composite, appears to be aimed toward Earth, while the opposite jet arches away from us. The opposite jet, which had been largely obscured in earlier views by thick clouds of cosmic dust, is now seen in vibrant yellow and green. This dual-jet view is more than pretty; it helps scientists compare the two sides of the outflow, measure differences in speed and density, and test models of how jets are launched from the inner accretion disk around the protostar. The image demonstrates that these jets are not only common; they carry significant energy. The speeds inferred from the data exceed one million kilometres per hour, and the energy involved is enough to have sweeping effects on the surrounding cloud. If a traveler could ride along at that pace, a journey from an ordinary house on Earth to the Moon would take less than twenty minutes. That speed translates to rapid clearing of material, creating cavities and channels that shape how stars accumulate mass and how the circumstellar disk evolves, which in turn affects where and how planets can form. According to researchers analyzing ALMA data, this jet power reshapes the birth environment.
Cool Fact
These jets look small when seen against the cold, black cloud that surrounds them, but in reality they span hundreds of times the size of our Solar System. The vast scale highlights the dramatic reach of star formation and the role these jets play in sculpting their birth environments, a view supported by observers studying young stellar objects.
These jets look tiny when seen against the cold, black cloud that surrounds them. In truth, they span hundreds of times the size of our entire Solar System. This vast scale shows the dramatic power of star formation and why researchers study these jets so closely. Observations of this type are part of modern astrophysical research.