The phrase "a planet on which" is correct and usable in written English.
It can be used when describing a specific planet that serves as a setting or context for an action or event.
Example: "Mars is a planet on which scientists believe there may have once been water."
Alternatives: "a planet where" or "a planet that".
IF EXTRATERRESTRIAL life were to exist, it would need a planet on which to evolve.
Intuitively, you might better understand the result by thinking of a group of people coming from a planet on which people are always born on the same day!
Imagine a wonderful world, a planet on which there was no threat of climate breakdown, no loss of freshwater, no antibiotic resistance, no obesity crisis, no terrorism, no war.
It's a film whose geography has a daunting grandeur: the vast and wintry plain, with its rocky forms, often looks like that of an alien planet, or a planet on which the characters we see are the last humans left.
What binds democratic America, Israel and India, then, is not merely that they are loathed by radical Muslims from Beirut to Borneo, but a shared commitment by most, if not all, Americans, Israelis and Indians to a planet on which all kinds of belief (and disbelief) have an equal right to thrive.
Imagine a planet on which people shared good news to stir others to do the same.
Observations from NASA's Kepler space telescope strongly suggest that, "basically every star has a planet, on average, which is pretty mind-boggling," Forgan says.
'For me, opera is dreams,' said Zeffirelli, 'and when I dream I create my own planet.' But the new Covent Garden Pagliacci - already seen in Rome, Los Angeles and Washington - is a nightmarish planet on which none of us would choose to live: a foul dystopia, contradicting the elegiac vistas of those other productions.
Little Dorrit is rich in epicycles: here a little flourish of Barnacles or an orbit for Mr F's aunt; there a moon called Bleeding Heart Yard; and, just over there, a minor planet on which Mrs General drives the proprieties in the form of elocution lessons for genteel young ladies ("papa, potatoes, poultry, prunes and prisms").
Humans have abandoned our scorched Earth in search of a new planet on which to settle.
Twin Earth, as Putnam presents it, is a (hypothetical) planet on which things look, taste, smell and feel exactly the way they do on Earth, but which have different underlying microscopic structures; for example, the stuff that fills the streams and comes out of the faucets, though it looks and tastes like water, has molecular structure XYZ rather than H2O.
