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On Earth’s surface, there are only a handful of high-quality astronomical sites that meet the requirements for very large next-generation facilities. In the context of scientific opportunities in time-domain astronomy, a good site on the Tibetan Plateau will bridge the longitudinal gap between the known best sites1,2 (all in the Western Hemisphere). The Tibetan Plateau is the highest plateau on Earth, with an average elevation of over 4,000 metres, and thus potentially provides very good opportunities for astronomy and particle astrophysics3–5. Here we report the results of three years of monitoring of testing an area at a local summit on Saishiteng Mountain near Lenghu Town in Qinghai Province. The altitudes of the potential locations are between 4,200 and 4,500 metres. An area of over 100,000 square kilometres surrounding Lenghu Town has a lower altitude of below 3,000 metres, with an extremely arid climate and unusually clear local sky (day and night)6. Of the nights at the site, 70 per cent have clear, photometric conditions, with a median seeing of 0.75 arcseconds. The median night temperature variation is only 2.4 degrees Celsius, indicating very stable local surface air. The precipitable water vapour is lower than 2 millimetres for 55 per cent of the night., The results of site testing at a local summit near Lenghu Town in Qinghai Province on the Tibetan Plateau indicate that the site is suitable as an astronomical observing site.

Since NASA introduced a double-blind review system to reduce bias, more successful proposals are coming from astronomers who haven’t been awarded observation time before. Since NASA introduced a double-blind review system to reduce bias, more successful proposals are coming from astronomers who haven’t been awarded observation time before.

Much of the progress in Astronomy has been driven by instrumental developments, from the first telescopes to fiber fed spectrographs. In this review we describe the field of astrophotonics, a combination of photonics and astronomical instrumentation that has the potential to drive the next generation of developements. We begin with the science cases that have been identified as possibly benefiting from astrophotonic devices. We then discuss devices, methods and developments in the field along with the advantages they provide. We conclude by describing possible future developments in the field and their influence on astronomy., 99 pages, 7 figures - Invited review article for The Astronomy and Astrophysics Review. Submitted on 9 Nov 2018, Resubmission 8 Nov 2020

Urban area mapping is an important application of remote sensing which aims at both estimation and change in land cover under the urban area. A major challenge being faced while analyzing Synthetic Aperture Radar (SAR) based remote sensing data is that there is a lot of similarity between highly vegetated urban areas and oriented urban targets with that of actual vegetation. This similarity between some urban areas and vegetation leads to misclassification of the urban area into forest cover. The present work is a precursor study for the dual-frequency L and S-band NASA-ISRO Synthetic Aperture Radar (NISAR) mission and aims at minimizing the misclassification of such highly vegetated and oriented urban targets into vegetation class with the help of deep learning. In this study, three machine learning algorithms Random Forest (RF), K-Nearest Neighbour (KNN), and Support Vector Machine (SVM) have been implemented along with a deep learning model DeepLabv3+ for semantic segmentation of Polarimetric SAR (PolSAR) data. It is a general perception that a large dataset is required for the successful implementation of any deep learning model but in the field of SAR based remote sensing, a major issue is the unavailability of a large benchmark labeled dataset for the implementation of deep learning algorithms from scratch. In current work, it has been shown that a pre-trained deep learning model DeepLabv3+ outperforms the machine learning algorithms for land use and land cover (LULC) classification task even with a small dataset using transfer learning. The highest pixel accuracy of 87.78% and overall pixel accuracy of 85.65% have been achieved with DeepLabv3+ and Random Forest performs best among the machine learning algorithms with overall pixel accuracy of 77.91% while SVM and KNN trail with an overall accuracy of 77.01% and 76.47% respectively. The highest precision of 0.9228 is recorded for the urban class for semantic segmentation task with DeepLabv3+ while machine learning algorithms SVM and RF gave comparable results with a precision of 0.8977 and 0.8958 respectively.

Working with the United Nations, scientists hope to establish standards for satellite ‘megaconstellations’ and reduce disruption of astronomical observations. Working with the United Nations, scientists hope to establish standards for satellite ‘megaconstellations’ and reduce disruption of astronomical observations.

Various space missions have measured the total solar irradiance (TSI) since 1978. Among them the experiments Precision Monitoring of Solar Variability (PREMOS) on the PICARD satellite (2010–2014) and the Variability of Irradiance and Gravity Oscillations (VIRGO) on the mission Solar and Heliospheric Observatory, which started in 1996 and is still operational. Like most TSI experiments, they employ a dual-channel approach with different exposure rates to track and correct the inevitable degradation of their radiometers. Until now, the process of degradation correction has been mostly a manual process based on assumed knowledge of the sensor hardware. Here we present a new data-driven process to assess and correct instrument degradation using a machine-learning and data fusion algorithm, that does not require deep knowledge of the sensor hardware. We apply the algorithm to the TSI records of PREMOS and VIRGO and compare the results to the previously published results. The data fusion part of the algorithm can also be used to combine data from different instruments and missions into a composite time series. Based on the fusion of the degradation-corrected VIRGO/PMO6 and VIRGO/DIARAD time series, we find no significant change (i.e −0.17±0.29 W/m2) between the TSI levels during the two most recent solar minima in 2008/09 and 2019/20. The new algorithm can be applied to any TSI experiment that employs a multi-channel philosophy for degradation tracking. It does not require deep technical knowledge of the individual radiometers., Scientific Reports, 11, ISSN:2045-2322

Its ‘decadal survey’ pitches big new space observatories, funding for large telescopes and a reckoning over social issues plaguing the field. Its ‘decadal survey’ pitches big new space observatories, funding for large telescopes and a reckoning over social issues plaguing the field.

Instrument platform crashed into the telescope’s dish, irrevocably ending the facility’s role in astronomy. Instrument platform crashed into the telescope’s dish, irrevocably ending the facility’s role in astronomy.

Some astronomers argue the flagship observatory — successor to the Hubble Space Telescope — will memorialize discrimination. Others are waiting for more evidence. Some astronomers argue the flagship observatory — successor to the Hubble Space Telescope — will memorialize discrimination. Others are waiting for more evidence.

Detective work reconstructs the final movements of the European Space Agency’s Philae probe. Detective work reconstructs the final movements of the European Space Agency’s Philae probe.

Most detailed report yet about the impact of giant satellite clusters says damage to observations is unavoidable — and offers mitigation strategies. Most detailed report yet about the impact of giant satellite clusters says damage to observations is unavoidable.

For the last four decades space exploration missions have searched for molecular life on planetary surfaces beyond Earth. Often pyrolysis gas chromatography mass spectrometry has been used as payload on such space exploration missions. These instruments have relatively low detection sensitivity and their measurements are often undermined by the presence of chloride salts and minerals. Currently, ocean worlds in the outer Solar System, such as the icy moons Europa and Enceladus, represent potentially habitable environments and are therefore prime targets for the search for biosignatures. For future space exploration missions, novel measurement concepts, capable of detecting low concentrations of biomolecules with significantly improved sensitivity and specificity are required. Here we report on a novel analytical technique for the detection of extremely low concentrations of amino acids using ORIGIN, a compact and lightweight laser desorption ionization – mass spectrometer designed and developed for in situ space exploration missions. The identified unique mass fragmentation patterns of amino acids coupled to a multi-position laser scan, allows for a robust identification and quantification of amino acids. With a detection limit of a few fmol mm−2, and the possibility for sub-fmol detection sensitivity, this measurement technique excels current space exploration systems by three orders of magnitude. Moreover, our detection method is not affected by chemical alterations through surface minerals and/or salts, such as NaCl that is expected to be present at the percent level on ocean worlds. Our results demonstrate that ORIGIN is a promising instrument for the detection of signatures of life and ready for upcoming space missions, such as the Europa Lander.

NASA’s high-flying SOFIA observatory has struggled to prove its scientific worth. NASA’s high-flying SOFIA observatory has struggled to prove its scientific worth.

Many major facilities have essentially shut down, but some are soldiering on. Many major facilities have essentially shut down, but some are soldiering on.

NASA halts work on the US$8.8-billion James Webb Space Telescope, which was due to launch next year. NASA halts work on the US$8.8-billion James Webb Space Telescope, which was due to launch next year.

First images from a new Sun observatory in Hawaii show churning plasma in unprecedented detail. First images from a new Sun observatory in Hawaii show churning plasma in unprecedented detail.

We present the Photometric Auxiliary System (PAS) attached to the 25-cm Photometric Telescope (PT) at Xinglong Observatory of National Astronomical Observatories, Chinese Academy of Sciences (NAOC). This PAS can provide real-time atmospheric extinction for other telescopes at the same station for flux calibration via observing standard stars, e.g. the 2.16-m reflector and 1-m telescope. Moreover, the real-time atmospheric extinction could act as a useful reference for other local telescopes regarding the adjustment of observing strategies, such as changing the exposure time, which is important for the observers. This PAS has been operated since February 2012, and we have obtained the $r$r-band atmospheric extinction of Xinglong Observatory from February 2012 to March 2018. With these data, we have analyzed the atmospheric extinction of Xinglong Observatory in detail.

Researchers are ramping up plans for living on the Moon. Researchers are ramping up plans for living on the Moon.

Chinese lunar spacecraft Chang’E-3 (CE3) and Chang’E5-T1 (CE5T1) were launched in 2013 and 2014, respectively and very long baseline interferometry (VLBI) observations were performed. Signal to noise ratio (SNR) of the Tianma (TM) station experienced peculiar variation, whereas SNRs of other stations were rather stable. Further, it happened only when observing spacecraft, and showed no such variation when performing astronomical observations. Moreover, it was distinctive on X band signals, whereas it was not noticed on S band signals. Analysis showed that the SNR variation was closely related with changing rate of elevation angle. Further investigations discovered that there were two sets of antenna control software at TM station, and the SNR variation originated from a bug in elevation control software used for observing spacecraft, not for astronomical observations. The bug caused big pointing error (around ± 30 as) on elevation angle of TM, which resulted in the peculiar SNR variation. It was not noticed on S band signals due to its relatively wide and flat main beam comparing with ± 30 as pointing error. However, the bug was fixed in software update in July, 2016, and the SNR of TM showed no such variation in 2017 and 2018.

The experimental efforts to detect the redshifted 21 cm signal from the Epoch of Reionization (EoR) are limited predominantly by the chromatic instrumental systematic effect. The delay spectrum methodology for 21 cm power spectrum measurements brought new attention to the critical impact of an antenna's chromaticity on the viability of making this measurement. This methodology established a straightforward relationship between time-domain response of an instrument and the power spectrum modes accessible to a 21 cm EoR experiment. We examine the performance of a prototype of the Hydrogen Epoch of Reionization Array (HERA) array element that is currently observing in Karoo desert, South Africa. We present a mathematical framework to derive the beam integrated frequency response of a HERA prototype element in reception from the return loss measurements between 100-200 MHz and determined the extent of additional foreground contamination in the delay space. The measurement reveals excess spectral structures in comparison to the simulation studies of the HERA element. Combined with the HERA data analysis pipeline that incorporates inverse covariance weighting in optimal quadratic estimation of power spectrum, we find that in spite of its departure from the simulated response, HERA prototype element satisfies the necessary criteria posed by the foreground attenuation limits and potentially can measure the power spectrum at spatial modes as low as $k_{\parallel} > 0.1h$~Mpc$^{-1}$. The work highlights a straightforward method for directly measuring an instrument response and assessing its impact on 21 cm EoR power spectrum measurements for future experiments that will use reflector-type antenna., 13 pages, 10 figures, Submitted to APJ

Derek Lowe draws lessons for today from a history of scientists’ experimental hacks. Derek Lowe draws lessons for today from a history of scientists’ experimental hacks.

In seafarers’ journals, Huw Lewis-Jones found a rich record of discoveries made in cramped cabins, on open decks and on forays to shore to bring back proofs of marvels. In seafarers’ journals, Huw Lewis-Jones found a rich record of discoveries made in cramped cabins, on open decks and on forays to shore to bring back proofs of marvels.

Nāmakanaui, a three-band submillimetre receiver, is currently being commissioned on the James Clerk Maxwell Telescope, report Instrumentation Specialists Izumi Mizuno and Chih-Chiang Han.

The agency found no evidence that the flagship observatory’s namesake was involved in anti-LGBT+ activities, but some say that Webb bears responsibility. The agency found no evidence that the flagship observatory’s namesake was involved in anti-LGBT+ activities, but some say that Webb bears responsibility.

New satellite image reveals the damage that shut down the facility, ending an era in astronomical observation. New satellite image reveals the damage that shut down the facility, ending an era in astronomical observation.

Six lessons from astronomy’s embrace of cloud computing. Six lessons from astronomy’s embrace of cloud computing.

Thirty Meter Telescope controversy is forcing scientists to grapple with how their research affects Indigenous peoples. Thirty Meter Telescope controversy is forcing scientists to grapple with how their research affects Indigenous peoples.

LUVOIR is a concept for a powerful, flexible space observatory to enable the first survey for exoplanets most similar to the Earth, search for signs of life in our Solar System and beyond, and revolutionize astrophysics in the twenty-first century.

The Ali Cosmic Microwave Background Polarization Telescope — currently under construction in the Ngari prefecture of Tibet — will search for primordial gravitational waves and probe the origin of the Universe.

The Event Horizon Telescope team wins a Breakthrough Prize — one of six awards covering physics, the life sciences and mathematics. The Event Horizon Telescope team wins a Breakthrough Prize — one of six awards covering physics, the life sciences and mathematics.

Construction of the Thirty Meter Telescope was supposed to start on 15 July. Construction of the Thirty Meter Telescope was supposed to start on 15 July.

The Thirty Meter Telescope project has faced years of legal challenges over planned Mauna Kea site. The Thirty Meter Telescope project has faced years of legal challenges over planned Mauna Kea site.

W e asked researchers what the breakthrough means for them and for science. W e asked researchers what the breakthrough means for them and for science.

See how astronomers took the first ever image of a black hole, at the heart of the galaxy M87. See how astronomers took the first ever image of a black hole, at the heart of the galaxy M87.

NASA’s New Horizons mission measures the distances of two stars from the outer reaches of the Solar System. NASA’s New Horizons mission measures the distances of two stars from the outer reaches of the Solar System.

Nature Astronomy Marios Karouzos You can also search for this author in PubMed Google Scholar Correspondence to Marios Karouzos. Reprints and Permissions Karouzos, M. On our bookshelf. Nat Astron 4, 830 (2020). https://doi.org/10.1038/s41550-020-1196-y Download citation Published: 10 September 2020 Issue Date: September 2020 DOI: https://doi.org/10.1038/s41550-020-1196-y

Latest launch includes ‘DarkSat’ prototype to reduce reflection from fleets of broadband Internet satellites. Latest launch includes ‘DarkSat’ prototype to reduce reflection from fleets of broadband Internet satellites.

As BepiColombo heads to Mercury — a long-neglected planet — Nature looks at which planets attract scientific missions, and why. As BepiColombo heads to Mercury — a long-neglected planet — Nature looks at which planets attract scientific missions, and why.

Elizabeth Gibney soaks up an exhibition blazing with hot science and cultural riches. Elizabeth Gibney soaks up an exhibition blazing with hot science and cultural riches.

Wanda Diaz Merced is a blind astronomer who says that converting astronomical data into sound could bring discoveries that conventional techniques miss. Wanda Diaz Merced is a blind astronomer who says that converting astronomical data into sound could bring discoveries that conventional techniques miss.

A Canadian radio telescope called CHIME is poised to record dozens of fast radio bursts each day. A Canadian radio telescope called CHIME is poised to record dozens of fast radio bursts each day.

If you want an astronaut to run your experiment alongside their many other responsibilities, keeping it simple is the key. If you want an astronaut to run your experiment alongside their many other responsibilities, keeping it simple is the key.

Improved understanding of conditions in the stratosphere are helping to produce more-accurate short-term climate forecasts. Improved understanding of conditions in the stratosphere are helping to produce more-accurate short-term climate forecasts.

Protestors in Hawaii have prevented construction for more than three weeks, and there is no sign of a resolution in sight. Protestors in Hawaii have prevented construction for more than three weeks, and there is no sign of a resolution in sight.

Michael Rowan-Robinson finds an account of NASA’s Spitzer mission gripping but narrowly focused. Michael Rowan-Robinson finds an account of NASA’s Spitzer mission gripping but narrowly focused.

T he Event Horizon Telescope’s global network of radio dishes has produced the first-ever direct image of a black hole and its event horizon. T he Event Horizon Telescope’s global network of radio dishes has produced the first-ever direct image of a black hole and its event horizon.

Gene-editing, open access and a biosafety rethink are set to shape research. Gene-editing, open access and a biosafety rethink are set to shape research.

The FAST telescope dish, stretching half a kilometre, will thrust China’s radio astronomers into a role of global leadership. The FAST telescope dish, stretching half a kilometre, will thrust China’s radio astronomers into a role of global leadership.