Lunar impact flashes have been monitored over the last 20 years for determining the mass frequency distribution of near-Earth objects in the cm-dm size range. In this work, using telescopic observations in R and I band from the NELIOTA database, impact flash temperatures are derived. They are found to range between approximately 1,300 and 5,800 K. In addition, it is also found that temperature values appear to have a distribution significantly broader than a Gaussian function, therefore making it difficult to estimate the impact flash luminous energy by assigning an average temperature. By measuring the flash temperatures and assuming a black body emission, here we derive the energy of the impacts. We also study the potential link of each event to individual meteoroid streams, which allows us to assign an impact velocity and therefore constrain the projectile mass. Impactor masses are found to range between a few to hundreds of grams, while their sizes are just of few centimetres following a size frequency distribution similar to other studies.

Temperatures of lunar impact flashes: mass and size distribution of small impactors hitting the Moon

On 8 October 2011, the Draconid meteor shower (IAU$$\#8$$#8, DRA) was predicted to cause two brief outbursts of meteors, visible from locations in Europe. For the first time, a European airborne meteor observation campaign was organized, supported by ground-based observations. Two aircraft were deployed from Kiruna, Sweden, carrying six scientists, 19 cameras and eight crew members. The flight geometry was chosen such that it was possible to obtain double-station observations of many meteors. The instrument setup on the aircraft as well as on the ground is described in full detail. The main peak from 1900-dust ejecta happened at the predicted time and at the predicted rate. The second peak was observed from the earlier flight and from the ground, and was caused most likely by trails ejected in the nineteenth century. A total of 250 meteors were observed, for which light curve data were derived. The trajectory, velocity, deceleration and orbit of 35 double station meteors were measured. The magnitude distribution index was high, as a result of which there was no excess of meteors near the horizon. The light curve proved to be extremely flat on average, which was unexpected. Observations of spectra allowed us to derive the compositional information of the Draconids meteoroids and showed an early release of sodium, usually interpreted as resulting from fragile meteoroids. Lessons learned from this experience are derived for future airborne meteor shower observation campaigns.

2011 Draconids: the first European airborne meteor observation campaign

/pdf/fragmentation-of-the-hayabusa-spacecraft-on-re-entry-29vs0ybfzc.pdf

Fragmentation of the HAYABUSA Spacecraft on Re-Entry

During the 1999 Leonids, an intensified HDTV camera was used for slitless meteor spectroscopy at visible and near-UV wavelengths in three night flights of the Leonid Multi-instrument Aircraft Campaign. The HDTV system provided a high dynamic range (digital 10-bit) and a wide field of view of 37 x 21 degrees. The maximum spectral sensitivity is at 405 nm, while the resolving power of the spectrograph was λ/Δλ ~ 250. Here, we report on the results for one particularly nice spectrum from a Leonid meteor at 03:24:40 UT. Numerous atomic emission lines of magnesium and iron were detected, with an excitation temperature of T = 5,000 ± 1,000. It is confirmed that sodium is released from the meteoroid earlier than iron and magnesium, just as in meteors of the 1998 Leonid shower. Rovibrational bands of N2 dominate the spectrum in the visible and near-IR. We searched for CN band emission at 389 nm, but could not detect it due to the overlap of numerous iron lines.

First Results of High-Definition TV Spectroscopic Observations of the 1999 Leonid Meteor Shower

Context. A bright fireball was observed above the Czech Republic on September 9, 2016, at 23:06:59 UT. Moreover, the video cameras at two different stations recorded eight fainter meteors flying on parallel atmospheric trajectories within less than 2 s. All the meteors belong to the September epsilon Perseid meteor shower. The measured proximity of all meteors during a very low activity meteor shower suggests that a cluster of meteors was observed.Aims. The goal of the paper is first to determine whether this event was a random occurrence or a real meteor cluster and second, if it was a cluster, to determine the epoch and at what distance from the Earth the separation of the particles occurred.Methods. The atmospheric trajectories of the observed meteors, masses, and relative distances of individual particles were determined using a double-station observation. According to the distances and masses of the particles, the most probable distance and time of fragmentation is determined.Results. The observed group of meteors is interpreted as the result of the orbital fragmentation of a bigger meteoroid. The fragmentation happened no earlier than 2 or 3 days before the encounter with the Earth at a distance smaller than ~0.08 AU from the Earth.

/pdf/september-epsilon-perseid-cluster-as-a-result-of-orbital-1cszpe251l.pdf

September epsilon Perseid cluster as a result of orbital fragmentation

Three short-duration “outbursts”, in which more than 20–40 meteors appeared in a few seconds, have been reported during a recent Leonid storm. The meteors in these events were extremely localized within a few hundred km, which should be caused by clusters of meteoroids. The existence of such clusters indicates the fragmentation of meteoroids during orbital motion in interplanetary space. Considering the extent of the spatial distribution, the fragmentation should have occurred at around the perihelion passage of the meteoroids just before encountering the Earth. This may cause a possible enhancement of smaller meteoroids, even in old dust trails. A possible example of similar clusters in the past meteor storm of Giacobinids is also noted.

/pdf/meteoroid-clusters-in-leonids-evidence-of-fragmentation-in-38rasb55rd.pdf

Meteoroid Clusters in Leonids: Evidence of Fragmentation in Space

Meteoroid clusters - evidence of fragmentation in space

Prominent activity of the 1998 Giacobinid meteor shower was observed from 11h UT through 15h UT on October 8 in Japan. We carried out a high-sensitivity HD-TV observation of this activity at the Dodaira station, and detected 341 Giacobinid meteors, along with 127 sporadic meteors. The peak activity was around 13h05m UT with an peak influx rate of meteoroids of 1.6 × 10−5km−2s−1 (magnitude ≤ +7). The peak corresponded to solar longitude 195.071° (equinox J2000.0), which is different from the expected maximum of the Giacobinids at the solar longitude 195.4° (equinox J2000.0). The duration of the peak activity is shorter than that of the previous outburst in 1985. The apparent brightness ratio of the faint meteors during our observation is about 2.1, which is a rather small value compared to previous displays.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/1999GL900195

HD TV observation of the strong activity of the Giacobinid meteor shower in 1998

Meteoroid clusters in Leonids: evidence of fragmentation in space

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Takema Hashimoto

Author Tools

Chat about Author

Papers

Meteoroid Clusters in Leonids: Evidence of Fragmentation in Space

Meteoroid clusters - evidence of fragmentation in space

HD TV observation of the strong activity of the Giacobinid meteor shower in 1998

Meteoroid clusters in Leonids: evidence of fragmentation in space