Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust—iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.

Portal origin URL: Glenn Researchers Study New, Futuristic Concept to Explore TitanPortal origin nid: 470927Published: Wednesday, May 12, 2021 - 09:00Featured (stick to top of list): noPortal text teaser: Glenn researchers are studying a futuristic concept to explore Titan.Portal image: Illustration of a rocket launching off the surface the Saturn’s moon Titan.

Nature, Published online: 13 May 2021; doi:10.1038/d41586-021-01258-7

The first spacecraft to visit interstellar space has now become the first to make continuous measurements of waves in that remote realm.

Portal origin URL: Webb’s Golden Mirror Wings Open One Last Time on EarthPortal origin nid: 470901Published: Tuesday, May 11, 2021 - 12:50Featured (stick to top of list): noPortal text teaser: For the last time while it is on Earth, the world’s largest and most powerful space science telescope opened its iconic primary mirror.Portal image: NASA’s James Webb Space Telescope is seen with one of its primary mirror wing panels fully extended during one of its final preflight tests.

Portal origin URL: As NASA’s Voyager 1 Surveys Interstellar Space, Its Density Measurements Are Making WavesPortal origin nid: 470876Published: Tuesday, May 11, 2021 - 11:00Featured (stick to top of list): noPortal text teaser: In the sparse collection of atoms that fills interstellar space, Voyager 1 has measured a long-lasting series of waves where it previously only detected sporadic bursts.Portal image: An artist concept depicting one of the twin Voyager spacecraft.

Portal origin URL: Hubble Gazes at a Cluster Full of Cosmic CluesPortal origin nid: 470811Published: Friday, May 7, 2021 - 08:45Featured (stick to top of list): noPortal text teaser: This detailed image features Abell 3827, a galaxy cluster that offers a wealth of exciting possibilities for study.Portal image: This detailed image features Abell 3827, a galaxy cluster that offers a wealth of exciting possibilities for study.

Portal origin URL: NASA’s OSIRIS-REx Spacecraft Heads for Earth with Asteroid SamplePortal origin nid: 470882Published: Monday, May 10, 2021 - 15:22Featured (stick to top of list): noPortal text teaser: After nearly five years in space, NASA’s Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft is on its way back to Earth with an abundance of rocks and dust from the near-Earth asteroid Bennu.Portal image: Asteroid Bennu ejecting particles from its surface on Jan. 19, created by combining two images from NASA’s OSIRIS-REx spacecraft

The observation of tiny deviations in the arrival times of radio pulses from neutron stars could be our first glimpse at gravitational waves from merging supermassive black holes.

The SKA Observatory formally came into effect last month following a 30-day notice period after the SKA convention was ratified by the UK government on 16 December.

New limits on the size of primordial gravitational waves have been set that are several orders of magnitude lower than the most sensitive laboratory experiment, as Edwin Cartlidge reports

An anti-reflective coating applied to some newer satellites in SpaceX’s Starlink constellation reduces their overall reflectivity by half but is less effective at certain wavelengths

Disagreements remain over the spectral signatures of phosphine in the atmosphere of Venus and whether life could survive in its hostile environment in the first place. James Dacey reports from the December online meeting of the American Geophysical Union

Nature, Published online: 05 May 2021; doi:10.1038/d41586-021-01171-z

The large-scale impact of magnetic fields on galaxy clusters has been unclear. Images from the MeerKAT radio telescope suggest that such fields can bend jets of particles ejected from massive black holes in galaxy clusters.

Nature, Published online: 05 May 2021; doi:10.1038/s41586-021-03434-1

Radio observations of the cluster Abell 3376, combined with numerical modelling, attribute the bent jets associated with the second-brightest galaxy in the cluster to an ordered magnetic field at the discontinuity.

Portal origin URL: Lunar Crater Radio Telescope: Illuminating the Cosmic Dark AgesPortal origin nid: 470764Published: Wednesday, May 5, 2021 - 11:55Featured (stick to top of list): noPortal text teaser: The early-stage NASA concept could see robots hang wire mesh in a crater on the Moon’s far side, creating a radio telescope to help probe the dawn of the universe.Portal image: This illustration depicts a conceptual Lunar Crater Radio Telescope on the Moon’s far side.

OSIRIS-REx Departs Asteroid BennuLearn More

Portal origin URL: Hubble Watches How a Giant Planet GrowsPortal origin nid: 470522Published: Thursday, April 29, 2021 - 10:45Featured (stick to top of list): noPortal text teaser: NASA’s Hubble Space Telescope is giving astronomers a rare look at a Jupiter-sized, still-forming planet that is feeding off material surrounding a young star.Portal image: This illustration of the newly forming exoplanet PDS 70b shows how material may be falling onto the giant world as it builds up mass.

Portal origin URL: NASA’s Parker Solar Probe Discovers Natural Radio Emission in Venus’ AtmospherePortal origin nid: 470646Published: Monday, May 3, 2021 - 09:00Featured (stick to top of list): noPortal text teaser: During a brief swing by Venus, Parker Solar Probe detected a natural radio signal that revealed the spacecraft had flown through the planet’s upper atmosphere. This was the first direct measurement of the Venusian atmosphere in nearly 30 years — and it looks quite different from Venus past.Portal image: A black and white satellite image showing one hemisphere of planet Venus against a backdrop of stars, with bright streaks throughout.