Progress of Research on Origins of Life in China

The development of Chinese space science and technology plays a great role in promoting the researches in the field of the origin of life. With the multidisciplinary cooperation, there are fruitful achievements in this research field obtained over the past two years. This report summarizes the major progress of the basic researches about the origin of life in China during 2018-2020.      

Overview of the Latest Scientific Results of China's Lunar Exploration Program

China's Chang'E-4 probe successfully landed on 3 January 2019 in Von Kármán crater within the South Pole-Aitken (SPA) basin on the lunar far side. Based on the data acquired by the scientific payloads onboard the lander and the rover, the researchers obtained the related information such as the geologic and tectonic setting of the landing area, compositional characteristics of the landing surface materials, dielectric permittivity and density of the lunar soil. The experiments confirmed the existence of materials dominated by olivine and low-calcium pyroxene in the SPA basin on the lunar far side, which preliminary revealed the geological evolution history of the SPA basin and even that of the early time lunar crust, as well as the tectonic setting and formation mechanism of the materials in the lunar interior. The researchers also inves-tigated the particle radiation, Linear Energy Transaction (LET) spectrum, and so forth on the lunar surface. The low-frequency radio observations were carried out on the lunar far side for the first time as well. This article summarizes the latest scientific results in the past years, focusing on the Chang'E-4 mission. Key words CLEP, Chang'E-4, Scientific objectives, Scientific payloads, Scientific results      

Progress of microgravity material research during the period of 2007—2009

Orbital experimental researches on crystal growth of Mn-doped GaSb and Bi2Se0.21Te2.79 are briefly summarized. The space experiments were completed in September of 2007 on broad the Foton-M3 satellite of Russia. Ground-based researches on the solidification behaviors of Al-Al3Ni, Al-Al2Cu, Ag-Cu eutectic, Al-Pb monotectic and Cu-Co peritectic alloys in a 50-meter-high drop tube were investigated. New experimental results on the ultrasonic field and the temperature recycling induced to chiral symmetry breaking of NaClO3 crystal also were reported in the present paper.      

Space Life Science of China

In the past two years, China's space life science has made great progress. Space biomedical and life science programs have carried out ground-based research for the first batch of projects, and are preparing to carry out space-based experiments along with the construction of China's space station. And space life science payload of the space station completed the development of positive samples. Thus, with the development of lunar exploration and Mars exploration projects, astrobiology research has also made a lot of basic achievements. On the basis of summarizing the development of space life science in China, this paper mainly introduces the important progress of payload technology and life science research.      

Goddard Robotic Telescope – Optical follow-up of GRBs and coordinated observations of AGNs

Since it is not possible to predict when a Gamma-Ray Burst (GRB) will occur or when Active Galactic Nucleus (AGN) flaring activity starts, follow-up/monitoring ground telescopes must be located as uniformly as possible all over the world in order to collect data simultaneously with Fermi and Swift detections. However, there is a distinct gap in follow-up coverage of telescopes in the eastern U.S. region based on the operations of Swift. Motivated by this fact, we have constructed a 14″ fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are (1) to follow-up Swift/Fermi GRBs and (2) to perform the coordinated optical observations of Fermi Large Area Telescope (LAT) AGN. Our telescope system consists of off-the-shelf hardware. With the focal reducer, we are able to match the field of view of Swift narrow instruments (20′ × 20′). We started scientific observations in mid-November 2008 and GRT has been fully remotely operated since August 2009. The 3σ upper limit in a 30 s exposure in the R filter is ∼15.4 mag; however, we can reach to ∼18 mag in a 600 s exposures. Due to the weather condition at the telescope site, our observing efficiency is 30–40% on average.     

Space Debris Research Progress of China

The rapid increase of space debris population has posed serious threaten to the safety of human space activities and became a global issue. How to enhance the technical capabilities of space debris threat coping ability is of great significance to the sustainable development of space activities, the further development, and utilization of outer space. In this paper, we describe space debris research progress of China on observation, collision avoidance, protection, mitigation, regulation, and standard during the last twenty years, and look forward to the future development direction of space debris.      

Progress of Earth Observation in China

China is expanding and sharing its capacity for Earth observation by developing sensors, platforms, and launch capabilities in tandem with growing lunar and deep space exploration. China is considering the Moon as a viable Earth observation platform to provide high-quality, planetary-scale data. The platform would produce consistent spatiotemporal data because of its long operational life and the geological stability of the Moon. China is also quickly improving its capabilities in processing and transforming Earth observation data into useful and practical information. Programs such as the Big Earth Data Science Engineering Program (CASEarth) provide opportunities to integrate data and develop "Big Earth Data" platforms to add value to data through analysis and integration. Such programs can offer products and services independently and in collaboration with international partners for data-driven decision support and policy development. With the rapid digital transformation of societies, and consequently increasing demand for big data and associated products, Digital Earth and the Digital Belt and Road Program (DBAR) allow Chinese experts to collaborate with international partners to integrate valuable Earth observation data in regional and global sustainable development.      

Influence of Fast Global Variations of Solar Magnetic Fields on Space Weather in Cycle 23

It is established that the large-scale and global magnetic fields in the Sun's atmosphere do not change smoothly, and long-lasting periods of gradual variations are superseded by fast structural changes of the global magnetic field. Periods of fast global changes on the Sun are accompanied by anomalous manifestations in the interplanetary space and in the geomagnetic field. There is a regular recurrence of these periods in each cycle of solar activity, and the periods are characterized by enhanced flaring activity that reflects fast changes in magnetic structures. Is demonstrated, that the fast changes have essential influencing on a condition of space weather, as most strong geophysical disturbances are connected to sporadic phenomena on the Sun. An explanation has been offered for the origin of anomalous geomagnetic disturbances that are unidentifiable in traditionally used solar activity indices. Is shown, main physical mechanism that leads to fast variations of the magnetic fields in the Sun's atmosphere is the reconnection process.     

On the early phase of relativistic solar particle events: Are there signatures of acceleration mechanism?

Many physical processes precede and accompany the solar energetic particles (SEP) occurrence on the Earth’s orbit. Explosive energy release on the Sun gives rise to a flare and a coronal mass ejection (CME). X-ray and gamma emissions are believed to be connected with flares. Radio emission is signature of disturbances traveling through the corona and interplanetary space. Particles can gain energy both in the flare and the accompanying wave processes. The beginning of the SEP events has the advantage of being the phase most close to the time of acceleration. Influence of interplanetary transport is minimal in the case of first arriving relativistic solar protons recorded by ground based neutron monitors in so called ground-level enhancements (GLE). The early phase of the SEP events attracts attention of many scientists searching for the understanding of particle acceleration. However, they come to the opposite conclusions. While some authors find arguments for coronal mass ejections as a sole accelerator of SEPs, others prove a flare to be the SEP origin. Here, the circumstances of SEP generation for several GLEs of the 23rd solar cycle are considered. Timing of X-ray, CME, and radio emissions shows a great variety from event to event. However, the time of particle ejection from the Sun is closer to maximum of X-ray emission than to any other phenomena considered. No correlation is found between the particle fluxes and the CME characteristics.     

Status of the Advanced Space-based Solar Observatory

The Advanced Space-based Solar Observatory (ASO-S) was formally approved at the end of 2017. In the past two years, ASO-S underwent its official Phase-B and Phase-C studies. The Phase-B study was successfully accomplished by the end of April 2019, and the Phase-C study is being now undertaken until August 2020. Then the flight model is planned to finish within 16 months. Around the end of 2021, ASO-S will be ready in the launch state. We briefly summarize the history of ASO-S, the phase-B studies, and the phase-C studies.      

Progress of Space Medicine Research in China

With the approaching of the Chinese Space Station (CSS) era, the focus of space medicine applications and related research has shifted to addressing the astronauts' health support in long-duration spaceflights, including nutrition, countermeasure against the physiological effects of weightlessness, medical monitoring and support, psychology status, etc., and accordingly the human experiments to simulate long-duration weightlessness have been carried out. Increasingly, basic research has been put forward in the key areas, such as space bone loss, cardiovascular dysfunction and the molecular mechanisms underlying radiobiological effects. Moreover, specific novel research fields, such as hypometabolism technology, were explored. The research projects in the field of space medicine experiment, as an important aspect of the Chinese Space Station's application, have been officially approved and launched.      

Planetary wave coupling of the atmosphere–ionosphere system during the Northern winter of 2008/2009

This paper presents the global spatial (latitude and altitude) structure and temporal variability of the ∼23-day ionospheric zonally symmetric (s = 0) planetary wave (PW) seen in the Northern winter of 2008/2009 (October 2008–March 2009). It is shown that these ∼23-day ionospheric oscillations are forced from PWs propagating from below. The COSMIC ionospheric parameters f_oF2 and h_mF2 and electron density at fixed altitudes and the SABER temperatures were utilized in order to define the waves which are present simultaneously in the atmosphere and ionosphere. The long-period PWs from the two data sets have been extracted through the same data analysis method. The similarity between the lower thermospheric ∼23-day (s = 0) temperature PW and its ionospheric electron density response provides valuable and strong experimental evidence for confirming the paradigm of atmosphere–ionosphere coupling.     

On the lunar node resonance of the orbital plane evolution of the Earth’s satellite orbits

This paper aims to investigate the effects of lunar node resonance on the circular medium Earth orbits (MEO). The dynamical model is established in classical Hamiltonian systems with the application of Lie transform to remove the non-resonant terms. Resonant condition, stability and phase structures are studied. The lunar node resonance occurs when the secular changing rates of the orbital node (with respect to the equator) and the lunar node (with respect to the ecliptic) form a simple integer ratio. The resonant conditions are satisfied for both inclined and equatorial orbits. The orbital plane would have long period (with typical timescales of several centuries) fluctuation due to the resonance.     

Summary of CNCOSPAR Activities 2006—2008

1 In Brief In July, 2006, we have successfully organized the 36th COSPAR Scientific Assembly in Beijing. This is the most important event for us during this period.     

Study of the influence of solar variability on a regional (Indian) climate: 1901–2007

We use Indian temperature data of more than 100 years to study the influence of solar activity on climate. We study the Sun–climate relationship by averaging solar and climate data at various time scales; decadal, solar activity and solar magnetic cycles. We also consider the minimum and maximum values of sunspot number (SSN) during each solar cycle. This parameter SSN is correlated better with Indian temperature when these data are averaged over solar magnetic polarity epochs (SSN maximum to maximum). Our results indicate that the solar variability may still be contributing to ongoing climate change and suggest for more investigations.     

Ionization effect of solar protons in the Earth atmosphere – Case study of the 20 January 2005 SEP event

The cosmic ray ground level enhancement on January 20, 2005 is among the largest recorded events in the history of cosmic ray measurements. The solar protons of MeV energies cause an excess of ionization in the atmosphere, specifically over polar caps following major solar disturbances. The ionization effect in the Earth atmosphere is obtained for various latitudes on the basis of solar proton energy spectra, reconstructed from GOES 11 measurements and subsequent full Monte Carlo simulation of cosmic ray induced atmospheric cascade. The estimation of ionization rates is based on a numerical model for cosmic ray induced ionization. The evolution of atmospheric cascade is performed with the CORSIKA 6.52 code using FLUKA 2006b and QGSJET II hadron interaction models. The atmospheric ion rate ionization is explicitly obtained for 40°N, 60°N and 80°N latitudes. The time evolution of obtained ion rates is presented. It is demonstrated that ionization effect is negative for 40°N and small for 60°N, because of accompanying Forbush decrease. The ionization effect is significant only in sub-polar and polar atmosphere during the major ground level enhancement of 20 January 2005.     

Research Progress of Interplanetary Physics in Mainland China

Significant progress has been made by Chinese scientists in research of interplanetary physics during the recent two years (2018-2020). These achievements are reflected at least in the following aspects:Activities in solar corona and lower solar atmosphere; solar wind and turbulence; filament/prominence, jets, flares, and radio bursts; active regions and solar eruptions; coronal mass ejections and their interplanetary counterparts; other interplanetary structures; space weather prediction methods; magnetic reconnection; Magnetohydrodynamic (MHD) numerical modeling; solar energetic particles, cosmic rays, and Forbush decreases; machine learning methods in space weather and other aspects. More than one hundred and forty papers in the academic journals have been published in these research directions. These fruitful achievements are obtained by Chinese scholars in solar physics and space physics either independently or through international collaborations. They greatly improve people's understanding of solar activities, solar eruptions, the corresponding space weather effects, and the Sun-Earth relations. Here we will give a very brief review on the research progress. However, it must be pointed out that this paper may not completely cover all achievements in this field due to our limited knowledge.