See attached abstract
Ground-based asteroid surveys have excelled at finding new near-Earth objects (NEOs) over the last three decades. However, the characterization of those bodies often lags due to the increased observation time needed to determine physical properties. With the Vera Rubin Observatory coming online later this year, this problem will only become more apparent. We present a newly funded NASA PDCO...
Thousands of Near Earth Objects (NEOs) are discovered every year, but only a small number of these have their compositions determined. In fall, 2024, we have begun a new program to determine the rough taxonomies and therefore compositions of at least ~1000 very small (absolute magnitude >25, or diameters <30 meters) NEOs over a three year period using the MuSCAT3/4 simultaneous four-channel...
The International Asteroid Warning Network (IAWN) is an organized network established in 2013 and sanctioned by the United Nations to coordinate worldwide entities involved in the detection, tracking, and characterization of Near-Earth Objects (NEOs). IAWN provides means of communicating and developing plans and protocols for responding to impact threats by obtaining and processing...
The OSIRIS-REx and Hayabusa2 missions yielded a wealth of data that is transforming the understanding of rubble-pile asteroids, providing unprecedented insights into their composition, structure, and evolution. Rubble-pile asteroids are highly porous, loosely bound collections of rocks and boulders held together primarily by gravity, with minimal cohesion, and measuring less than a few...
Asteroids show significant variation in the polarisation properties of their reflected light, which are diagnostic of their surface mineralogy, geometric albedo, and texture. These properties have historically been used to characterise them; however, this remains an under-explored method for their taxonomic classification. Potentially Hazardous Asteroids (PHAs) form a particularly important...
(469219) Kamo`oalewa is a small near-Earth asteroid, which is currently a quasi-satellite of Earth. Lightcurve measurements revealed a rotation period of about 30 minutes, while the spectrum is compatible with that of S-type asteroids. This object has been selected as the target of the sample-return Tianwen-2 mission of the China National Space Administration.
In early 2024, we performed...
Introduction: After the successful launch of the ESA/HERA mission [1] on 7 October 2024 it is timely to recall what we have learned from The NASA Double Asteroid Redirection Test (DART) impact [2] and ASI/Light Italian Cubesat for Imaging of Asteroids (LICIACube) [3] mission. DART was the first space mission that successfully demonstrated the kinetic impactor technique for planetary...
Near-Earth objects provide a considerable risk to mankind. To comprehend the issue and safeguard our planet, it is essential to monitor and advance technologies to alleviate the risk. NEOs are mineral-rich and potentially provide fresh resources for future space research missions. Monitoring Near-Earth Objects (NEOs) may enhance our understanding of solar system origin as well.
By analyzing...
In this work, we apply jet transport techniques as implemented in the open-source software package NEOs.jl [1, 2] to the problem of orbit determination and impact probability predictions for asteroid 2024 PDC25, the hypothetical scenario for the 9th Planetary Defense Conference 2025. From the astrometry file available for 2024 PDC25 at Epoch 1 [3], we perform a preliminary orbit determination...
The IRAC camera on the Spitzer Space Telescope observed 2175 Near Earth Objects (NEOs) during its Warm Mission phase, across three large surveys and a small number of dedicated small projects. We present the final reprocessing of the NEO data and infrared photometry in the 3.6 μ and 4.5 μ regimes [1]. The window of observation has allowed for a small number of complete light curves to be...
Asteroids with sizes below a few km are mostly believed to be loose aggregates bound together primarily by self-gravity, known as rubble-piles. Historically, rubble-pile asteroids have been treated as essentially cohesionless aggregates. Recent evidence from high-resolution spacecraft in-situ observations (e.g. Hayabusa2 and OSIRIS-REx missions) show very low values for cohesion on the surface...
At the time of writing this abstract, eleven asteroids had been discovered in the sky prior to their impact on Earth. The first one was detected in 2008, but in 2024 alone, four were discovered. This shows that the number of detection is steadily increasing, and we should expect this trend to continue in the coming years with the ongoing improvement of observational techniques and the...
The near-Earth binary asteroid (65803) Didymos gained significant scientific attention after the successful impact of NASA's DART mission on its secondary, Dimorphos, validating kinetic impact as a planetary defence strategy (Thomas et al., 2023). This study builds on previous analyses of particle dynamics on Didymos' surface (Trogolo et al.,2023). Using updated physical parameters (Naidu et...
Rapid reconnaissance flyby missions are the fastest means of obtaining asteroid characterization data in a planetary defense scenario. However, the small masses of potentially hazardous asteroids (PHAs) require unreasonably or impossibly close flyby distances to achieve useful mass measurements with ground-based tracking, the current state of practice. This capability gap limits the value of...
The successful demonstration of NASA DART mission success in testing the kinetic impact as a planetary defense technique will be enhanced even more by the scientific observations of the upcoming ESA Hera mission. The spacecraft, launched on October 2024, and now on his way to the Didymos-Dimorphos binary asteroid system, will understand in detail the effect of the DART impact and the outcome...
The South African Astronomical Observatory (SAAO) has made significant contributions to the observation and characterisation of near-Earth asteroids (NEAs), supporting global planetary defense efforts. Located near the town of Sutherland in the Northern Cape, SAAO's diverse array of telescopes, ranging from 10-m to 1-m in diameter, offers capabilities in spectroscopy, multi-filter photometry,...
The analysis of mm-wavelength thermal emission from near-Earth asteroids can be used to constrain thermophysical (thermal inertia, emissivity) and radiative (index of refraction, loss tangent) properties of the top few centimeters of regolith. These properties can be used to constrain the regolith porosity. For near-Earth asteroids (NEAs), regolith porosity is one of the physical properties...
This work presents the results of an observation campaign conducted in the second half of 2024 and which will last until the first half of 2025, aimed at the photometric characterization in the BVRcIc bands of the brightest near-Earth asteroids observable from the northern hemisphere.
The observations were mainly conducted using the “G.D. Cassini” 1.52-m F/4.8 Ritchey-Chrétien telescope of...
Keywords: NEOs, NEAs, Near Earth Space
Decameter size NEAs are of particular interest in the context of the NEO problem because the frequency of collisions with such bodies is much higher than that of larger bodies and the consequences of collisions can be still significant. So far, the population of decameter bodies has been poorly studied since they are difficult to observe. To build an...
The Planetary Science Team at the University of Alicante (Spain) is currently formed by 10 researchers dedicated to modeling and physical characterization of small bodies in the Solar System. Here are some current topics:
\textbf{IEO Survey}: Currently, 34 objects have an Interior Earth Orbit (IEO) that don't pose an immediate risk but may eventually lead to Earth-crossing trajectories due...
Near-Earth asteroids (NEAs) provide valuable opportunities to study the physical and structural properties of small bodies. While most asteroids have rotation periods longer than the "cohesionless spin barrier"—a 2.2-hour limit beyond which rubble-pile asteroids would break apart due to centrifugal forces—some rotate much faster, challenging current understanding of the internal structure of...
Asteroids with MOID less than 1 AU are of significant scientific interest due to their potential for close approaches to Earth's orbit. Characterizing their physical properties—size, shape, and spin state—provides essential insights into their evolution, taxonomic classification, and potential impact threat.
In this work, we present a thorough analysis of the absolute magnitude and slope...
We present the use of the University of Tasmania's (UTAS) optical and radio telescopes to conduct observations of near-Earth objects from 2021 to 2024. The Canberra Deep Space Communications Complex transmitted at 7159.45 MHz, with the radar echo detected by the UTAS radio telescopes. The method of accounting for the Doppler shift between the stations and the near-Earth object will be...
Keywords: Near-Earth Objects, Radar, radio telescopes, binary asteroid
From 2019 to 2022, the ESA funded the “NEO Observation Concepts for Radar Systems” pilot project, aimed at the future development of a European radar system for NEOs, enhancing planetary defense, mission planning, and advancing the scientific study of Near-Earth Objects. Contributions from INAF, SpaceDyS, and the...
Meteoroids are the solid remnants of asteroids and comets, ranging from micrometres to decametres in size. Upon entering Earth’s atmosphere, they follow a ballistic trajectory that is partly determined by their composition and internal structure. They display a variety of behaviours including harmless disintegration, meteorite deposition (e.g: Nqweba), explosive airbursts (e.g: Chelyabinsk),...
Rapid reconnaissance and characterization of asteroids and comets is one of the stated priorities for planetary defense in the 2023 decadal survey on planetary science and astrobiology1. Traditional asteroid reconnaissance spacecraft like OSIRIS-REx, Lucy, or Psyche have years long development cycle to launch, extensive post-launch trajectory arrival times, and cost hundreds of millions of...
To assess the risk of an impact from a Near Earth Object (NEO), it is crucial to estimate both the size and density of the object. These estimations can be more easily inferred if the albedo of the object is known. In this context, polarization observations are a key tool for swiftly determining the size of a NEO, and consequently, their potential threat to Earth.
The degree of linear...
Keywords: Long Period Comets, Meteor Showers, Early Warning
We describe a software tool that can be used for planning dedicated searches for long-period comets based on the projection of their meteoroid streams against the sky.
Long period comets with orbital periods in the range 250 to 4000 years produce dense enough meteoroid streams to be detected as meteor showers on Earth [1]. Those...
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Acknowledgement
Funded by the European Union (ERC, TRACES, 101077758). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.
Keywords: Near-Earth objects, radar observations, radio telescopes
Astronomical radar observations have been used to probe surfaces of all the solid planets and many smaller bodies in the solar system. This led to a growing interest in the use of radar to characterize near-Earth asteroids (NEAs) and determine their orbits more precisely. There
is a three-fold motivation for performing radar...
Abstract
Apollo and ATEN class asteroids representing a hazardous form of deep space debris, are now being routinely monitored and researched from the Southern Hemisphere longitude of Australia. A bistatic radar and optical program developing since 2015, brings together the resources of the Universities of New South Wales, Tasmania, Western Australia, Curtin and Federal agencies CSIRO and...
Telescopic characterisation of asteroids and the study of meteorite geochemistry in the lab are fundamentally linked: they study the same objects. However the two disciplines have been mostly disjointed so far, if we exclude the handful of asteroid sample return missions. If we can detect and characterise an asteroid while it is in space, and recover meteoritic samples of it after it impacts,...
Keywords: Near-Earth Objects, Astrometry, Orbit determination
The increasing availability of astrometric data from a wide range of observatories requires a full statistical evaluation of their performances to ensure reliable orbit determination for small bodies, particularly Near-Earth Objects (NEOs). This study presents a systematic statistical analysis of astrometric post-fit residuals for...
The powerful method of stellar occultations is an unbeatable technique uniquely approaching, in some aspects, the performances of planetary space missions. It allows to derive, from ground using small aperture telescopes, asteroids' positions at Gaia-level accuracy [F22], thus extending the time- coverage of Gaia ESA mission. Moreover, it allows to determine the physical size of these...
The Near-Earth Objects Coordination Centre (NEOCC) is the main component of the Planetary Defence Office (PDO) within ESA's Space Safety Programme. Its mission is to support and coordinate the observations of small Solar System bodies and to assess and track the threats they may pose to Earth. Central to this mission is Aegis (1), an automated orbit determination and impact monitoring system...
The binary asteroid (285263)1998 QE2 is one of the largest PHAs known, measuring 3.2km with a 800m satellite, with the last known closest approach to Earth of 0.039 au (~15 lunar distances) on May 31st, 2013. During the 2013 approach, high-resolution radar data was collected at the Arecibo Observatory and Goldstone helping with physical and dynamical characterization of the system. With the...