Archives

November 2017


Is there life beyond Earth in the cosmos? Astronomers looking for signs have found that our Milky Way galaxy teems with exoplanets, some with conditions that could be right for extraterrestrial life.

Stratosphere circulation is important to interpret abundances of photo-chemically produced compounds like ozone that we aim to observe to assess habitability of exoplanets.

Received via Iridium 29 November 2017 4:30:03 PM EST: "Hi Keith The earlier weather forecasts were spot on and we have had blowing snow and high winds most of the day forcing us to retreat into our various tents for the day."

We study the prospects for life on planets with subsurface oceans, and find that a wide range of planets can exist in diverse habitats with relatively thin ice envelopes

Plate tectonics is a geophysical process currently unique to Earth, has an important role in regulating the Earth's climate, and may be better understood by identifying rocky planets outside our solar system with tectonic activity.

It has been established theoretically that atmospheric thermal tides on rocky planets can lead to significant modifications of rotational evolution, both close to synchronous rotation and at faster rotations if certain resonant conditions are met.

We analyze the interiors of HD~219134~b and c, which are among the coolest super Earths detected thus far. Without using spectroscopic measurements, we aim at constraining if the possible atmospheres are hydrogen-rich or hydrogen-poor.

We report the first interstellar detection of DC7N and six 13C-bearing isotopologues of HC7N toward the dark cloud TMC-1 through observations with the Green Bank Telescope, and confirm the recent detection of HC515N.

Two young worms are the first offspring in a Mars soil experiment at Wageningen University & Research. Biologist Wieger Wamelink found them in a Mars soil simulant that he obtained from NASA.

In the underground rivers and flooded caves of Mexico's Yucatan Peninsula, where Mayan lore described a fantastical underworld, scientists have found a cryptic world in its own right.

This message was received via Iridium on 28 November 28, 2017 8:13:28 AM EST "We are in our last week of work here at Untersee before heading back to Novo on the 6th. Hope to get in a few more dives for sample collection and imagery beneath the ice, and we have to pull experiments that are ongoing in the lake right now. Unfortunately our weather is likely to change tonight and tomorrow and Thursday may not be great for work."

During the accretion of Titan, impact heating may have been sufficient to allow the global melting of water ice and the release of volatile compounds, mainly constituted of CO2, CH4 and NH3.

Understanding the impact of active M-dwarf stars on the atmospheric equilibrium and surface conditions of a habitable zone Earth-like planet is key to assessing M dwarf planet habitability.

The amount of biomass -- life -- in Earth's ancient oceans may have been limited due to low recycling of the key nutrient phosphorus, according to new research by the University of Washington and the University of St. Andrews in Scotland.

Dale Andersen sent this message on 26 November 2017 at :09:26 AM EST: "We are working pretty hard while taking advantage of the nice days we have had recently. I made a dive beneath the 3.5 m thick ice-cover yesterday afternoon to collect a few sediment cores at 17 m (depth) and make observations of the lake basin in the area around the dive hole."

Dale Andersen sent this message on 23 November 2017 at 4:08:18 AM EST: "Yesterday started very nicely with sunshine and little or no winds so the morning hours were pretty productive. But by noon, katabatics let loose a barrage of winds and blowing snow that shut us down for most activities in the afternoon."

Dale Andersen sent this message on 22 November 2017 3:00:56 AM EST: "We have a second day of nice weather with clear skies and light winds which is quite helpful to us."

We study the dynamical evolution of the TRAPPIST-1 system under the influence of orbital circularization through tidal interaction with the central star.

Black holes growing via the accretion of gas emit radiation that can photoevaporate the atmospheres of nearby planets.

Earth's climate, mantle, and core interact over geologic timescales.

Proxima~Centauri is known as the closest star from the Sun. Recently, radial velocity observations revealed the existence of an Earth--mass planet around it. With an orbital period of ∼11 days, the surface of Proxima Centauri b is temperate and might be habitable.

Dark features previously proposed as evidence for significant liquid water flowing on Mars have now been identified as granular flows, where sand and dust move rather than liquid water.

Dale Andersen sent this message from: Lat -71.33293 Lon 13.45381 on 20 November 2017 5:22:14 AM EST: "Hi Keith: Looks like our weather is improving, but we still have strong gusting winds (25-30 knots and occasional 40 knot gusts) with blowing snow, but it is much nicer than yesterday so hopefully this afternoon and tomorrow it will settle down and we can get back to our field work.

Using the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), we map the temporal variability of water ice absorption bands over the near-polar ice mound in Louth crater, Mars.

We use more than a decade of radial velocity measurements for α Cen A, B, and Proxima Centauri from HARPS, CHIRON, and UVES to identify the Msini and orbital periods of planets that could have been detected if they existed.

Dale Andersen sent this message from: Lat -71.33293 Lon 13.45381 on 19 November 2017 at 1:43:18 AM EST: "The weather here is pretty bad with high winds gusting at 45-50 knots and a lot of blowing snow causing whiteout conditions here at the lake.

A New Physical Model Explains The Origin Of Earth's Water.

We explore the occurrence and detectability of planet-planet occultations (PPOs) in exoplanet systems. These are events during which a planet occults the disk of another planet in the same system, imparting a small photometric signal as its thermal or reflected light is blocked.

Dale Andersen sent this message from: Lat -71.332844 Lon 13.453746 on 15 November 2017 11:29:14 AM EST: Hi Keith: We had another productive day with good weather here at Lake Untersee. Our skies were clear and with the exception of a couple of hours, the winds were light which made working outside on the lake much easier.

Reservoirs of oxygen-rich iron between the Earth's core and mantle could have played a major role in Earth's history, including the breakup of supercontinents, drastic changes in Earth's atmospheric makeup, and the creation of life, according to recent work from an international research team published in National Science Review.

A team working with ESO's High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile has found that the red dwarf star Ross 128 is orbited by a low-mass exoplanet every 9.9 days.

The scenario and the efficiency of water transport by icy asteroids and comets are still amongst the most important unresolved questions about the early phases of planetary systems.

Dale Andersen sent this message via Iridium satphone on 14 November 2017 1:09:15 PM EST Hi Keith: We are settling in and our camp is fully operational - all the tents up, gear more or less sorted and science equipment has been opened and we are starting to work on the various tasks at hand.

Using data from MALT90 (Millimetre Astronomy Legacy Team Survey at 90 GHz), we present molecular line study of a sample of ATLASGAL (APEX Telescope Large Area Survey of the Galaxy) clumps.

The location of a repeat plume detected at Europa is found to be coincident with the strongest ionosphere detection made by Galileo radio occultation in 1997.

Many organic molecules have been observed in the interstellar medium thanks to advances in radioastronomy, and very recently the presence of urea was also suggested. While those molecules were observed, it is not clear what the mechanisms responsible to their formation are.

An asteroid, also known as the Chicxulub Impactor, hit Earth some 66 million years ago, causing a crater 180 km wide. The impact of the asteroid heated organic matter in rocks and ejected it into the atmosphere, forming soot in the stratosphere.

Dale Andersen sent this message via Garmin in Reach from: Lat -71.332877 Lon 13.453317 on November 2017 at 11:39:37 AM EST. "Arrived. Untersee all ok". You can interact with the map here - note the viewing options in the upper right hand corner. Click on images for larger view.

Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth.

Precise and, if possible, accurate characterization of exoplanets cannot be dissociated from the characterization of their host stars.

We present an overview of sources of biologically relevant astrophysical radiation and effects of that radiation on organisms and their habitats. We consider both electromagnetic and particle radiation, with an emphasis on ionizing radiation and ultraviolet light, all of which can impact organisms directly as well as indirectly through modifications of their habitats.

The signatures of planets hosted by M dwarfs are more readily detected with transit photometry and radial velocity methods than those of planets around larger stars.

Dale Andersen sent this message via Iridium satphone on 8 November 2017 at 2:54:15 AM EST: "Hi Keith: We are still at Novo waiting for the weather to improve long enough to begin the traverse to Lake Untersee. Unfortunately we have had a series of storms pass by dropping a fair amount of snow.

We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary body of the solar system, such as the Galilean moons of Jupiter.

Molecular oxygen, O2, was recently detected in comet 67P by the ROSINA instrument on board the Rosetta spacecraft with a surprisingly high abundance of 4 % relative to H2O, making O2 the fourth most abundant in comet 67P.

A main goal of NASA's Kepler Mission is to establish the frequency of potentially habitable Earth-size planets (eta Earth).

Early Earth may have hosted a biologically-mediated global organic haze during the Archean eon (3.8-2.5 billion years ago).

Enough heat to power hydrothermal activity inside Saturn's ocean moon Enceladus for billions of years could be generated through tidal friction if the moon has a highly porous core, a new study finds, working in favour of the moon as a potentially habitable world.

Chemists at The Scripps Research Institute (TSRI) have found a compound that may have been a crucial factor in the origins of life on Earth.

The chemical composition of stars that have orbiting planets provides important clues about the frequency, architecture, and composition of exoplanet systems.

Massive stars, which terminate their evolution as core collapse supernovae, are theoretically predicted to eject more than 1E-5 solar masses of the radioisotope 60Fe.

Dale Andersen sent this message via Iridium satphone on 5 November 2017 at 1:55:43 am EDT:

NASA scientists and engineers have conceived and plan to build an ambitious submillimeter-wave or radio instrument to study the composition of geysers spewing water vapor and icy particles from the south pole of Saturn's small moon, Enceladus.

Dale Andersen sent this message via Garmin inRreach on 4 November 2017 at 8:44 am EDT from: Lat -70.774999 Lon 11.837554

The deadline is quickly approaching for the BoldlyGo Institute crowdfunding campaign to search for Earth-like planets circling Alpha Centauri. All donations are now being doubled - matched dollar-for-dollar by a generous donor.

Some exoplanets shine brighter than others in the search for life beyond the solar system.

Proxima Centauri, the star closest to our Sun, is known to host at least one terrestrial planet candidate in a temperate orbit. Here we report the ALMA detection of the star at 1.3 mm wavelength and the discovery of a belt of dust orbiting around it at distances ranging between 1 and 4 au, approximately.