Stories by Harry Stevens

America’s surprise economic powerhouse: North Dakota

Data: U.S. Census Bureau via Brookings, Opportunity Insights; Note: “Economic mobility” is measured as the average income percentile of children whose parents were in the lowest income quartile; Graphic: Harry Stevens/Axios

The newest U.S. economic hotspot is not in or near Silicon Valley, New York, or any tech corridor, but in the northern plains — specifically oil-infused North Dakota.

What's happening: This region, in the middle-north of the country, leads the nation in a string of economic indicators since the financial crash, according to a new report by the Brookings Institution. And North Dakota is atop the bunch.

All the planets we've found in the Milky Way — so far

Data: PHL’s Exoplanet Catalog. Note: Earth Similarity Index was introduced by Schulze-Makuch et. al., Astrobiology, 2011. ESI is calculated with respect to a planet’s size and the energy received by its star; it is not necessarily a corollary for potential habitability. Chart: Harry Stevens/Axios

Astronomers have confirmed the existence of more than 3,000 "exoplanets" — planets that aren't in our solar system, orbiting stars other than our sun. The chart above shows how similar they are to Earth.

Why it matters: A small number of discovered exoplanets — those that are small enough to have a rocky surface and the right distance from their star to hold liquid water — may be able to support life, and to provide clues about the evolution of our own planet.

The massive number of Democratic candidates for 2018

Source: Federal Election Commission; Chart: Harry Stevens/Axios

More Democratic congressional candidates have competed in the 2018 election cycle than either party attracted in any cycle since 1980, according to an Axios analysis of Federal Election Commission data.

Why it matters: The last time either party drew this many congressional candidates was in 2010, when Tea Party rallies and grassroots opposition to President Barack Obama brought a new generation of conservative Republicans to Congress.