A novel bacterial strain, designed Q4-3, was isolated from a soil sample obtained from Qilian grassland, Qinghai, China. Phylogenetic, phenotypic, chemotaxonomic and molecular analyses were performed on the new isolate. Cells were Gram-stain-positive, facultatively anaerobic, spore-forming, motile rods with peritrichous flagella. Phylogenetic analysis based on 16S rRNA gene sequences placed strain Q4-3 in the genus Paenibacillus, and its closest relatives were Paenibacillus odorifer JCM 21743, Paenibacillus typhae DSM 25190, Paenibacillus borealis DSM 13188 and Paenibacillus etheri DSM 29760 with 16S rRNA gene sequence similarities of 98.12, 97.89, 97.63 and 97.6 %, respectively. The isolate grew at 4-37 °C (optimum 28-30 °C), at pH 6.0-10.0 (optimum pH 7.5) and with 0-3 %(w/v) NaCl (optimum 1 %). The DNA of strain Q4-3 was determined to be 48.6 mol%. The predominant menaquinone was MK-7 and the diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. Anteiso-C15 : 0 (55.5 %), iso-C16 : 0 (14.5 %) and C16 : 0 (13.3 %) were the major fatty acids. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified lipid. Based on these results, strain Q4-3 is considered to represent a novel of the genus Paenibacillus, for which the name Paenibacillusalbidus nov. is proposed. The type strain is Q4-3 (=CGMCC 1.16134=KCTC 33911).
Sending astronauts to Mars will be a milestone of future deep space exploration activities. However, energetic particle radiation in deep space and in the Mars environment is a major risk to the health of future human explorers. The nominal Martian surface radiation field contains primary Galactic Cosmic Ray (GCR) particles and secondary particles generated in the Martian atmosphere and the regolith. Some of these secondary particles may propagate upward and even be detected at the orbit of Mars contributing to the orbit radiation. Studying the Mars orbit radiation environment is critical for planning future Mars orbital missions. Therefore, we calculate the Martian orbit radiation dose rate considering the primary GCR spectra provided by the Badhwar-O’Neill 2014 model and the secondary particles modeled by the state-of-the-art Atmospheric Radiation Interaction Simulator. Specifically, we calculate the integral dose rate of each particle type and its dependence on orbit height, surface pressure, and solar modulation intensity. Our analysis shows that modulation intensity is the most dominating factor and that different surface pressures make less than a 1% impact. We also derive the sensitive energy range of detected particles contributing to the dose rate and further validate our prediction against the measured data by Liulin-MO on TGO at a circular orbit around Mars. This may conduce to predicting the radiation risks in Mars orbit and providing constructive reference parameters for the crewed space industry.
On 28 October 2021, solar eruptions caused intense and long‐lasting solar energetic particle (SEP) flux enhancements observed by spacecraft located over a wide longitudinal range in the heliosphere. SEPs arriving at Earth caused the 73rd ground level enhancement (GLE) event recorded by ground‐based neutron monitors. In particular, this is also the first GLE event seen on the surface of three planetary bodies, Earth, Moon, and Mars, by particle and radiation detectors as shown in this study. We derive the event‐integrated proton spectrum from measurements by near‐Earth spacecraft and predict the lunar and martian surface radiation levels using particle transport models. Event doses at the lunar and martian surfaces of previous GLE events are also modeled and compared with the current event. This statistical and comparative study advances our understanding of potential radiation risks induced by extreme SEP events for future human explorations of the Moon and Mars.
We present two multipoint interplanetary coronal mass ejections (ICMEs) detected by the Tianwen-1 and Mars Atmosphere and Volatile Evolution spacecraft at Mars and the BepiColombo (0.56 au ∼0.67 au) upstream of Mars from 2021 December 5 to 31. This is the first time that BepiColombo is used as an upstream solar wind monitor ahead of Mars and that Tianwen-1 is used to investigate the magnetic field characteristics of ICMEs at Mars. The Heliospheric Upwind Extrapolation time model was used to connect the multiple in situ observations and the coronagraph observations from STEREO/SECCHI and SOHO/LASCO. The first fast coronal mass ejection event (∼761.2 km s−1), which erupted on December 4, impacted Mars centrally and grazed BepiColombo by its western flank. The ambient slow solar wind decelerated the west flank of the ICME, implying that the ICME event was significantly distorted by the solar wind structure. The second slow ICME event (∼390.7 km s−1) underwent an acceleration from its eruption to a distance within 0.69 au and then traveled with the constant velocity of the ambient solar wind. These findings highlight the importance of background solar wind in determining the interplanetary evolution and global morphology of ICMEs up to Mars distance. Observations from multiple locations are invaluable for space weather studies at Mars and merit more exploration in the future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.