Every confirmed planet outside the solar system, drawn live from the NASA Exoplanet Archive. The interesting part is not the points. It is the empty regions, because most of them are empty for reasons that have nothing to do with what is out there. Turn on the detection contours and watch the shape of the sample separate from the shape of the population.
Counted from whatever the archive returned this session, and recounted whenever you change a filter. Anything derived is computed here from the catalog values rather than read from a column, so it is reproducible from the numbers you can see.
A catalog of discoveries is not a sample of the population. It is a sample of what the instruments could reach, and the two look nothing alike. Three biases do almost all of the damage, and all three can be drawn as contours on these axes, which is what the overlay buttons do.
A transit needs the orbit to be edge on. The geometric probability is roughly the stellar radius divided by the orbital distance, so it falls as the orbit widens. A hot Jupiter three days out from a Sun-like star transits about one time in eight. Earth, from the same star, transits about one time in two hundred. Nothing about that ratio is a statement about how common either planet is.
A transit has to be deep enough to see. The depth is the square of the ratio of the radii, so it depends brutally on the star. Earth across the Sun is 84 parts per million. The same Earth across a small M dwarf is more than a thousand. That single fact is why the small planets we know about orbit small stars, and it is a property of our telescopes rather than of planet formation.
A radial velocity detection needs the star to move. The semi-amplitude scales with planet mass and falls off as the cube root of the period, so long-period and low-mass planets hide together. Earth moves the Sun by nine centimeters a second. State of the art spectrographs are working at a few tens of centimeters a second, and stellar surface activity produces a comparable signal that is not a planet at all.
Turn on iso-depth in the period-radius view and the lower edge of the transiting population lies along a contour, not along anything physical. That is the instrument, drawn.
There is a real feature in the size distribution called the radius valley, or the Fulton gap: a deficit somewhere between roughly one and a half and two Earth radii, with planets piling up on either side of it. It is usually read as being about atmospheres rather than cores. A rocky core with a thin hydrogen envelope sits above the gap; strip that envelope, by photoevaporation from the young star or by the core's own leftover heat, and the same core drops below it. The gap is the fast crossing between the two states, so few planets are caught inside it.
You will probably not see it in this histogram, and that is worth understanding. The published result comes from a single survey with stellar radii deliberately refined, because a planet radius is only ever as good as the stellar radius it was measured against. This page pools every survey together, and the radius errors differ from one to the next. Convolve a real gap with a spread of measurement errors wider than the gap and it fills in. That is what you are looking at.
Checked against a real catalog of five thousand planets rather than asserted: the bins either side of the claimed gap run 181, 212, 162, 191 and 226 planets. There is a dip in the middle of that, and it is not larger than the scatter between its neighbours. Calling it a detection would be reading a result into noise.
So the band is drawn on the plot as a claim from the literature, positioned where the literature puts it, and not as a result of this histogram. Change the bin width and watch what happens: a feature that survives from coarse bins to fine ones is worth something, and one that only appears at a single width is an artefact of the binning. The control is deliberately prominent for exactly that reason.
In the period-radius view, look at short periods and intermediate sizes: a few days, and roughly three to ten Earth radii. There is a wedge there that is close to empty, and this one is not a detection bias. Large planets on short orbits are the easiest thing in the entire catalog to find, so if they were there we would have them by the thousand.
The usual reading is that it is carved by evaporation. Close in, the star's ultraviolet output strips a hydrogen envelope quickly, and a Neptune is mostly envelope. Below a certain mass the planet cannot hold on, so it either arrives as a bare core or becomes one. Anything that keeps its envelope at those separations has to be massive enough to hold it, which puts it up with the hot Jupiters.
Turn on the iso-depth and transit probability contours while looking at the desert. Both run the wrong way to explain it: this region is easier to detect than the regions around it that are full. That is what makes it interesting rather than an artefact.
The catalog supplies masses, radii, periods, separations and stellar parameters. Anything else on this page is derived from those, in the browser, using closed-form expressions: transit depth as the square of the radius ratio, transit probability from stellar radius over orbital distance, semi-major axis from Kepler's third law, equilibrium temperature from the stellar temperature and the dilution of its flux, radial velocity semi-amplitude from the standard expression, and bulk density from mass and radius.
Each was checked against a system whose answer is independently known. Kepler's third law returns 1.000 au for a 365.256 day orbit around one solar mass. Earth across the Sun gives a depth of 84 parts per million and a transit probability of 0.47 percent. Jupiter gives 1.06 percent and a stellar wobble of 12.5 meters per second; Earth gives 8.9 centimeters per second. Earth's equilibrium temperature comes out at 254 K with a Bond albedo of 0.306, and 278 K with no albedo at all.
One detail worth stating because it will otherwise look like an error. Densities here use the equatorial radii that the archive's units are defined against, so Earth comes out at 5.50 grams per cubic centimeter and Jupiter at 1.24. The textbook values, 5.51 and 1.33, use mean volumetric radii instead. The ratio between the two conventions accounts for the difference exactly, and being consistent with the catalog matters more here than matching a textbook.
Equilibrium temperature assumes even redistribution of heat and zero albedo unless you say otherwise, which no real planet obeys. It is a scale, not a forecast, and it is not a statement about whether anything could live there.
The page queries the NASA Exoplanet Archive's table of composite planetary parameters directly from your browser, over its public interface. Nothing is proxied through this site, which has no server to proxy with, and the query is visible in the source. The result is kept in this browser's own storage for a day so that a second visit does not re-download it.
No copy of the catalog is bundled with this page. That is deliberate. A stale snapshot shipped alongside the code would silently become wrong, and a made up one would be very much worse: this page is only worth anything if every point on it is a real measurement someone actually made. If the archive cannot be reached, the plot stays empty and says so, and offers you the archive's own download so you can drop the file in yourself.
The composite parameter table gives one row per planet, assembled by the archive from across the literature, which means a single row can combine a mass from one paper with a radius from another. That is the right table for looking at the population and the wrong one for studying an individual system. For that, go to the archive and read the papers.
Uncertainties are not plotted. Many of these masses are known to a few percent and others to a factor of two, and drawing them all as identical dots hides that completely. Where a mass came from a mass-radius relation rather than from a measurement, it is not an independent number at all, which is why the mass quality filter exists and why the mass-radius view defaults to warning you about it.