The findings lend credence to two previously proposed suspects in the case: leftover heat from planetary formation and intense radiation from the host stars. In some previously proposed models of atmosphere loss, 'some of these planets were 10 times larger at the starts of their lives.' 'The overarching point is that planets are not the static spheres of rocks and gas we sometimes tend to think of them as,' says David, a research fellow at the Flatiron Institute's Center for Computational Astrophysics (CCA) in New York City. The researchers report their findings May 14 in The Astronomical Journal. The gap, in other words, is the chasm between the largest-size super-Earths and the smallest-size mini-Neptunes that can still retain their atmospheres.

As time goes on, the radius gap shifts as larger and larger mini-Neptunes make the jump, transforming into larger and larger super-Earths. By losing their gas, the mini-Neptunes 'jump' the planet radius gap and become super-Earths. The implication, the researchers propose, is that some mini-Neptunes shrink drastically over billions of years as their atmospheres leak away, leaving behind only a solid core. While the scarcest size for younger planets was about 1.6 times Earth's radius, it's about 1.8 times Earth's radius at older ages. The least common planet radii from the younger set were smaller on average than the least common ones from the older set, they found. They divvied up exoplanets into two groups-young and old-and reassessed the gap. A team of researchers led by the Flatiron Institute's Trevor David investigated whether the radius gap changes as planets age. The new clue arose from a fresh way of looking at the data. Since discovering this 'radius gap' in 2017, scientists have been sleuthing out why there are so few midsize heavenly bodies. That's the middle ground between rocky super-Earths and larger, gas-shrouded planets called mini-Neptunes. However, it is suspected that the planet either had a direct collision with an Earth-sized planet or a near-miss with the gravity from the other celestial body pushing the planet off its axis.While planet-hunting missions have discovered thousands of worlds orbiting distant stars, there's a severe scarcity of exoplanets that measure between 1.5 and two times Earth's radius. The exact cause of Uranus’ tilt is not known. Uranus, however, spins with a tilt of 98 degrees ensuring the planet’s poles directly face the sun as it does. Planets in our solar system orbit the sun spinning upright like a top. One of the many debated oddities of the planet includes its tilt.

Since its discovery, the Voyager flyby and time under the gaze of the Hubble Telescope, Uranus has hinted at the mysteries it holds. Where Saturn, a close neighbor (relatively) of the featureless planet, has spent 13 years under Cassini’s gaze, our knowledge of Uranus is almost entirely based on a single flyby mission by the Voyager 2 spacecraft in 1986. The first planet to be discovered using a telescope, Uranus has since held a relatively low priority for Earth’s space exploration community. However, from the little we do know about the planet, it is clear that it holds mysteries that many are itching to solve. Uranus is a featureless oddity in our solar system, a turquoise marble that has remained largely unstudied.

Mini orbiter by planet time