Plant Seeds as Model Vectors for the Transfer of Life Through Space

We consider plant seeds as terrestrial models for a vectored life form that could protect biological information in space. Seeds consist of maternal tissue surrounding and protecting an embryo. Some seeds resist deleterious conditions found in space: ultra low vacuum, extreme temperatures and radiation, including intense UV light. In a receptive environment, seeds could liberate a viable embryo, viable higher cells or a viable free-living organism (an endosymbiont or endophyte). Even if viability is lost, seeds still contain functional macro and small molecules (DNA, RNA, proteins, amino acids, lipids, etc.) that could provide the chemical basis for starting or modifying life. The possible release of endophytes or endosymbionts from a seed-like space traveler suggests that multiple domains of life, defined in DNA sequence phylogenies, could be disseminated simultaneously from Earth. We consider the possibility of exospermia, the outward transfer of life, as well as introspermia, the inward transfer of life–both as a contemporary and ancient events.     

2003年8月太阳活动区AR0442内的暗条爆发及其相关现象的研究

利用色球Ha单色像、TRACE和SOHO／EITEUV单色像、SOH0／LASCO白光日冕观测及SOH0／MDI光球磁图，对2003年8月25日日面AR0442边界上2个暗条爆发的不同动力学行为及与之相关的耀斑、耀斑后环和CME等现象进行了分析。主要结论如下：(1)2个暗条的激活态和爆发过程有明显不同：暗条F1先变粗变黑，出现明显分叉，然后表现为whiplike爆发；而暗条F2一部分先消失，其余部分出现水平的轴向运动，最后F2整体爆发。(2)2个暗条的爆发机制是不同的：F1的爆发可能与新浮磁流密切相关，而F2的爆发与F1爆发产生的双带耀斑的分离运动和相互作用密切相关。     

A Check on the Variations of Earth‘s Rotation with an Ancient Solar Eclipse

We address the relation between an ancient total eclipse, which occurred on A.D.1542 August 11 and the variation of Earth‘‘s rotation. The total eclipse was recorded in some ancient Chinese books, especially in local chronicles. Some of the documents include useful information for determining the location of the totality zone. The parameters of the eclipse are calculated by using the DE406 Ephemeris.A high-precision value of AT which expresses the variation of the Earth‘‘s rotation,of about 300 ～ 380 s, is obtained.     

太阳辐射对北京地区跨断层形变测量的影响

本文研究了太阳辐射对北京地区跨断层垂直形变测量的干扰,指出太阳辐射对该地区测点引起的最大热形变量可达0.72mm。在形变资料分析中,必须排除这种干扰的影响。     

Peculiarities of the microwave emission from active regions generating intense solar flares

RATAN-600 multiwavelength observations of the Sun reveal sharp spectral inhomogeneities in the polarized radiation from active regions that produce intense flares. These events occur in a wide range of radio fluxes (0.05–10 s.f.u.) in a relatively narrow wavelength range (2–5 cm). They are detected on time scales from several hours to several days before and during an intense flare. We analyze the detected events and their relationship to the preliminary phase of intense flares. Significant statistical material was obtained in 2001. The new flare-plasma properties can be used to test existing solar-flare models and to develop new criteria of flaring activity.     

X-Ray Emission From Comet Hale–Bopp

The discovery of X-ray emission from comets has created a number of questions about the physical mechanism producing the radiation. There are now a variety of explanations for the emission, from thermal bremsstrahlung of electrons off neutrals or dust, to charge exchange induced emission from solar wind ions, to scattering of solar X-rays from attogram dust, to reconnection of solar magnetic field lines. In an effort to understand this new phenomenon, we observed but failed to detect in the X-ray the very dusty and active comet C/Hale-Bopp 1995 O1 over a two year period, September 1996 to December 1997, using the ROSAT HRI imaging photometer at 0.1–2.0 keV and the ASCA SIS imaging spectrometer at 0.5–10.0 keV. The results of our Hale-Bopp non-detections, when combined with spectroscopic imaging 0.08–1.0 keV observations of the comet by EUVE and BeppoSAX, show that the emission has the same spectral shape and strong variability seen in other comets. Comparison of the ROSAT photometry of the comet to our ROSAT database of 8 comets strongly suggests that the overall X-ray faintness of the comet was due to an emission mechanism coupled to gas, and not dust, in the comet’s coma. This revised version was published online in July 2006 with corrections to the Cover Date.     

检验行星潮汐对太阳耀斑的影响

第19太阳周内6．5年中的1119个≥2-级太阳耀斑，相对于木星和金星的日面经度观测分布为Pj（L）和Pv（L）．五种理论分布假设为：（1）均匀随机分布；（2)均匀随机十横向潮汐力分布；（3）均匀随机十竖向潮汐力分布；（4）均匀随机十潮汐力模量分布；（5）均匀随机十横向潮汐力和竖向潮汐力分布．观测和理论分布的X2拟合优度检验表明：在较严格的显著性水平上（α＜0.01），五种理论分布假设都能接受；但到α≈0.35（木星）和α≈0．175（金星）；则拒绝第1种假设，而应接受第2－5种假设，尤以第5种理论分布假设为佳.Pj和Pv中难于避免许多重要干扰但仍可检测出.所以，行星潮汐影响太阳因素；故其中，可检测的行星潮汐成分只能较小；活动，仍是种显著的效应．     

超大型矿床密集区和大陆岩石圈形成与太阳系起源和演化的成因联系研究动态

在太阳系星云盘形成尘层过程中，由于浓差分带机制形成一系列夹心尘环。由C尘环中的C群球粒陨石物质聚合成的碳质球粒陨石小行星，在4．1～3．9Ga时陨击地球，导致了大陆酸性岩石的形成以及现今全球超大型矿床的分布格局。     

The limitations of NEO-uniformitarianism

The geological and biological sciences have gradually dispensed with the nineteenth-century concept of substantive uniformitarianism - or gradualism - whereby the physical and biological features of our planet are assumed to have been brought about by the long-term accumulation of small changes. The catastrophist alternative sees the changes as being wrought largely by discrete, exceptional events; one such type of event is an impact by a substantial asteroid or comet. It is argued here that scientists working on small solar system bodies generally still labour under a form of this gradualism, in that a conventional starting point is to presume a steady-state, and what is seen now is assumed to be diagnostic of the long-term average conditions. This is here termed NEO-uniformitarianism, the NEO referring to Near-Earth Objects. It is maintained herein that this area of science needs to revise its philosophical basis by allowing catastrophist principles to be entertained; that is, the presumption of a steady-state needs to be rejected until such time as evidence to support it is revealed. It is argued that the weight of evidence favours the contrary. For example, evidence is outlined for (a) Variations in the terrestrial cratering rate, disallowing any equating of the crater record with the presently-observed large impactor population; (b) The presence of significant NEO complexes which may be due to giant comet disintegrations within the last 20 kyr, hence solving the problem of the supply of short-period comets; (c) A misbalance between the present supply of meteoroids, there being too many to be supplied by presently-observed comets and also a surplus above the population needed to maintain the interplanetary dust complex; and (d) A substantial variation in the interplanetary dust flux in the past 20 kyr, as might be expected from (b and c).