Joe Palca Joe Palca is a science correspondent for NPR.
Joe Palca 2010
Stories By

Joe Palca

When Mars is "in opposition," it, Earth and the sun are all in alignment. (Note: This is a diagram meant to illustrate the concept of opposition. It is not drawn to scale.) Alyson Hurt/NPR hide caption

toggle caption
Alyson Hurt/NPR

Celestial Lineup Makes For A Very Bright Mars

  • Download
  • <iframe src="https://www.npr.org/player/embed/632620769/632939544" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

This is the south polar cap of Mars as it appeared to the Mars Orbiter Camera on the Mars Global Surveyor on April 17, 2000. An underground lake was found near here. NASA/JPL/MSSS, hide caption

toggle caption
NASA/JPL/MSSS,

Underground Lake Found On Mars Beneath A Mile Of Ice

  • Download
  • <iframe src="https://www.npr.org/player/embed/632222129/632411357" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

An early prototype of the silicon-chip-sized particle accelerator that physicists at Stanford are working on. Eventually, miniature accelerators might have a role in radiating tumors, the scientists say. SLAC National Accelerator Laboratory hide caption

toggle caption
SLAC National Accelerator Laboratory

Physicists Go Small: Let's Put A Particle Accelerator On A Chip

  • Download
  • <iframe src="https://www.npr.org/player/embed/630101228/630246579" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

The planet Jupiter now has a total of 79 identified moons. QAI Publishing/UIG via Getty Images hide caption

toggle caption
QAI Publishing/UIG via Getty Images

Galileo Would Be Stunned: Jupiter Now Has 79 Moons

  • Download
  • <iframe src="https://www.npr.org/player/embed/629396121/629896553" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

This artist's impression shows the dust torus around a super-massive black hole. Black holes lurk at the centers of active galaxies. The jets emanating from the black hole send neutrinos hurtling into space. ESA/NASA/the AVO project/Paolo Padovani hide caption

toggle caption
ESA/NASA/the AVO project/Paolo Padovani

A 4 Billion Light-Year Journey Ends At The South Pole

  • Download
  • <iframe src="https://www.npr.org/player/embed/628142995/628546651" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Global map of Mars showing a growing dust storm as of June 6, 2018. The map was produced by the Mars Color Imager (MARCI) camera on NASA's Mars Reconnaissance Orbiter spacecraft. NASA/JPL-Caltech/MSSS hide caption

toggle caption
NASA/JPL-Caltech/MSSS

Giant Dust Storm On Mars Threatening To End NASA's Opportunity Rover

  • Download
  • <iframe src="https://www.npr.org/player/embed/619557735/619672968" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Two rock samples taken by NASA's Curiosity rover were found to contain organic molecules. NASA/JPL-Caltech/MSSS hide caption

toggle caption
NASA/JPL-Caltech/MSSS

NASA's Curiosity Rover Finds Chemical Building Blocks For Life On Mars

  • Download
  • <iframe src="https://www.npr.org/player/embed/617235884/618163037" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Detectors inside MiniBooNE experiment Courtesy Fermilab hide caption

toggle caption
Courtesy Fermilab

Physicists Say They Have Evidence For A New Fundamental Particle

  • Download
  • <iframe src="https://www.npr.org/player/embed/616803143/617029607" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

This red blood cell is swollen by the malaria parasite. In this image from a transmission electron micrograph, the blood cell has been colored red and the single-cell malaria parasite has been colored green. Dr. Tony Brain/Science Source hide caption

toggle caption
Dr. Tony Brain/Science Source

How A Cheap Magnet Might Help Detect Malaria

  • Download
  • <iframe src="https://www.npr.org/player/embed/613099137/614195933" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

This is an artist's concept of a plume of water vapor thought to be ejected off of the frigid, icy surface of the Jovian moon Europa, located 500 million miles from the sun. NASA, ESA, and K. Retherford hide caption

toggle caption
NASA, ESA, and K. Retherford

Icy Moon Of Jupiter Spews Water Plumes Into Space

  • Download
  • <iframe src="https://www.npr.org/player/embed/610357799/611199742" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

An artist's rendition of NASA's InSight lander, which is expected to launch on Saturday morning. InSight will monitor the Red Planet's seismic activity and internal temperature. NASA/JPL-CalTech hide caption

toggle caption
NASA/JPL-CalTech

NASA Is Heading Back To Mars To Peer Inside The Red Planet

  • Download
  • <iframe src="https://www.npr.org/player/embed/608448614/608583080" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

An image from an electron microscope shows a type II alveolar cell, found in the air sacs of lungs. In the cell's cytoplasm (pink) are lamellar bodies (purple), which contain surfactant. SPL/Science Source hide caption

toggle caption
SPL/Science Source

Experimental Lung Treatment Could Make Breathing Easier

  • Download
  • <iframe src="https://www.npr.org/player/embed/607373219/607483531" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

First responders in the Marina District disaster zone after an earthquake on October 17, 1989 in San Francisco, Calif. Otto Greule Jr/Getty Images hide caption

toggle caption
Otto Greule Jr/Getty Images

Betting On Artificial Intelligence To Guide Earthquake Response

  • Download
  • <iframe src="https://www.npr.org/player/embed/595564470/604423995" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Somewhat random numbers Joe Palca/NPR hide caption

toggle caption
Joe Palca/NPR

Really Random Numbers

  • Download
  • <iframe src="https://www.npr.org/player/embed/601111484/601759949" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript